[单选题]Trees should only be pruned when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves the cutting away of overgrown and unwanted branches, and the inexperienced gardener can be encouraged by the thought that more damage results from doing it unnecessarily than from leaving the tree to grow in its own way. First, pruning may be done to make sure that trees have a desired shape or size. The object may be to get a tree of the right height, and at the same time to help the growth of small side branches which will thicken its appearance or give it a special shape. Secondly, pruning may be done to make the tree healthier. You may cut diseased or dead wood, or branches that are rubbing against each other and thus cause wounds. The health of a tree may be encouraged by removing branches that are blocking up the centre and so preventing the free movement of air. One result of pruning is that an open wound is left on the tree and this provides an easy entry for disease, but it is a wound that will heal. Often there is a race between the healing and the disease as to whether the tree will live or die, so that there is a period when the tree is at risk. It should be the aim of every gardener to reduce which has been pruned smooth and clean, for healing will be slowed down by roughness. You should allow the cut surface to dry for a few hurts and then paint it with one of the substances available from garden shops produced especially for this purpose. Pruning is usually without interference from the leaves and also it is very unlikely that the cuts you make will bleed. If this does happen, it is, of course, impossible to paint them properly. ?What was the author's purpose when writing this passage?
A.To give practical instruction for pruning a tree.
B.To give a general description of pruning.
C.To explain how trees develop diseases.
D.To discuss different methods of pruning.

[单选题]Trees should only be pruned when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves the cutting away of overgrown and unwanted branches, and the inexperienced gardener can be encouraged by the thought that more damage results from doing it unnecessarily than from leaving the tree to grow in its own way. First, pruning may be done to make sure that trees have a desired shape or size. The object may be to get a tree of the right height, and at the same time to help the growth of small side branches which will thicken its appearance or give it a special shape. Secondly, pruning may be done to make the tree healthier. You may cut diseased or dead wood, or branches that are rubbing against each other and thus cause wounds. The health of a tree may be encouraged by removing branches that are blocking up the centre and so preventing the free movement of air. One result of pruning is that an open wound is left on the tree and this provides an easy entry for disease, but it is a wound that will heal. Often there is a race between the healing and the disease as to whether the tree will live or die, so that there is a period when the tree is at risk. It should be the aim of every gardener to reduce which has been pruned smooth and clean, for healing will be slowed down by roughness. You should allow the cut surface to dry for a few hurts and then paint it with one of the substances available from garden shops produced especially for this purpose. Pruning is usually without interference from the leaves and also it is very unlikely that the cuts you make will bleed. If this does happen, it is, of course, impossible to paint them properly. A good gardener prunes a tree__________.
A.at intervals throughout the year
B.as quickly as possible
C.occasionally when necessary
D.regular every winter

[单选题]Only when the CIA Director David was forced to resignthat it's hard to keep our e-mail secret.
A.we realized
B.realized we
C.did we realize
D.we did realize

[单选题]Only when he was told that his precious stone was but an artificial gem did the old man realize that he had been cheated of almost RMB 100,000 yuan.
A.superficial
B.custom-made
C.ready-made
D.man-made

[不定项选择题]Man can eventually land on Venus only when
A.the algae have done their work
B.the atmosphere becomes cooler
C.there is oxygen
D.it rains there

[单选题]Only when humanity began to get its food in a more （ ） way was there time for other things, like sports games and entertainment activities.
A.predictive
B.provocative
C.protective
D.productive

[单选题]Only when we hurried to the airport __________the fight was canceled.
A.we found
B.did we find
C.have we found
D.we have found

[不定项选择题]共用题干 第二篇

Credit Card Only Works When Spoken To

A credit card that will not work unless it hears its owner's voice could become an
important weapon in the fight against fraud（欺骗）.
The card requires users to give a spoken password that it recognizes using a built-in
voice-recognition chip.The idea is to prevent thieves using a stolen card or fraudsters using
someone else's credit card details to buy goods online.
A model built by engineers at Beepcard in Santa Monica,California,represents the
first attempt to pack a microphone,a loudspeaker,a battery and a voice-recognition chip
into a standard-sized credit card.
They are not quite there yet:the card is the length and width of an ordinary credit card,
but it is still about three times as thick.The company now plans to make it thinner.
The voice card is based on an earlier Beepcard technology designed to prevent fraud in
online transactions.This earlier card has no microphone,but has a built-in loudspeaker
that it uses to " squawk"（发出叫声）a voice ID signal via a computer's microphone to an
online server.
By verifying（证实）that the signal matches the card details,the server can establish
that the user is not simply keying in a credit card number but actually has the card to hand.
The ID code changes each time the card is used in a pre-ordered sequence that only the server knows.
This prevents fraudsters recording the beeps, noting the card details and then playing
back the audible ID when they key in the details later.But this earlier technology cannot
prevent fraudulent use of stolen cards.The new one can.
The new voice card also identifies itself by its ID squawk,but it will not do this until it
has verified the legitimate（合法的）user's spoken password. Thieves will be unable to use
the card because even if they knew the password they would have to be able to copy the
owner's voice with a high degree of accuracy.
The challenge for Beepcard has been to develop voice-recognition and audio circuitry
that can be powered by a mini battery embedded（嵌入的）in a credit card. To maximize
battery life,the electronics are only switched on when the card is being used.Pressing a
button on the card's surface prompts it to utter "Say your password" in female voice.If the
voice-recognition software proves that the password is authentic（真实的）,it sends its ID
squawk which the server then identifies,allowing the transaction to proceed. What can we learn from the last paragraph about the voice card?
A.Only female voice passwords could be recognized.
B.Further improvement should be made to extend battery life.
C.There is no!imit to its application.
D.Female customers like to use it.