[填空题]We plant and care for trees in _____ many benefits they give us.

[单项选择]Though people plant many trees in this area every year, the top of some hills is still ______.
A) open C) empty
B) bare D) blank

[单项选择]By cutting down trees we __ the natural home of birds and animals.
A. harm
B. hurt
C. injure
D. damage

[填空题]Although many calls we make are absolutely unnecessary, mobile phones can surely bring us convenience.

[简答题]We all know that we should take better care of ourselves, relax more, and have more fun at work (and elsewhere, as well) , but it’s easy to overlook the opportunities to do just that be cause of the daily work priorities that consume our lives. Here are some ideas for learning to take action in your work life.

[填空题]In many parts of the world, large numbers of trees ______ (遭到砍伐) and the eco logical balance of nature has been disturbed.

[填空题]How many steps must we take when we read a map
We have to take ______.

[单项选择]We were delighted to find the trees planted a year before（）very tall.
A. growing
B. being grown
C. having been growing
D. grown

[填空题]We had so many things that we couldn’t move them by ourselves.
We had too many things ______ move them by ourselves.

[单项选择]Trees are so common arid quiet that we pay them little mind. What, for instance, should we answer when asked to name the biggest living thing Earth has ever seen Dinosaurs Blue whales No, the largest sequoias in northern California weigh more than six blue whales. The tallest redwoods and Australian eucalyptus trees tower more than 300 feet high, three times the length of the greatest dinosaur.
(71) Some bristlecone pine trees in the American West are more than 4, 000 years old, seedlings at the time the Egyptians were building the Pyramids.
Trees sustain our lives and our planet in a thousand practical ways. This morning at breakfast—in your wood-framed house, on your wooden kitchen table—you might have enjoyed orange juice or a grapefruit. Both come to use from trees. Over your French toast you may have sprinkled cinnamon and nutmeg, the powdered bark and nuts of tropical trees. That quart of maple syrup on your table was boiled down from roughly 10 gallons of sap f
A. For centuries, the Chinese have derived medicines from the ginkgo tree.
B. Through photosynthesis, an acre of trees produces enough oxygen to sustain three humans.
C. As scientists unlock the secrets of trees, they uncover surprising tacts.
D. Trees have always been green machines, producing substances that humans learned to use.
E. You think, at 150 or more years, giant tortoises can live a long time
F. And the morning newspaper was printed on the processed wood pulp we call paper.

[单项选择]I don't care （） we are invited to the dinner or not.
A. if
B. that
C. whether
D. what

[单项选择]We （　） on it for many hours but we have not yet reached any conclusion.
A. work
B. have been worked
C. have been working
D. are working

[单项选择]There are many beautiful trees on ______ side of the street.
A. each
B. both
C. all

[填空题]How many steps are involved in the care of lenses