[单项选择]You ______ all those calculations ! We have a computer to do that sort of things.
A. needn’t have done B. shouldn’t have done
C. must not have done D. could not have done

[单项选择]You ______ all those calculations ! We have a computer to do that sort of things.
A. needn’t have done B. shouldn’t have done
C. must not have done D. could not have done

[单项选择]You （） all those calculations! We have a computer to do that sort of thing.
A. needn’t have done
B. must not have done
C. shouldn’t have done
D. can not have done

[简答题]You______(本来不必进行) all those calculations. We have a computer to do that sort of thing.

[填空题]If you are alone, go for help before you have completed the most urgent first -aid measures

[单项选择]Where have you been We （　） you back earlier.
A. were excepting
B. are excepting
C. have excepted
D. except

[填空题] Pain
All of us have felt pain. we have cut ourselves. We have been burned. Or we have had headaches. Some of us suffer pain rarely. (46)
Pain can take complete control of our body and mind, making it impossible to move and even to think. Yet we need pain. Without It, we would not know if we have hurt ourselves. It is our body’s warning system. (47)
Pain is the most common reason we go to a doctor. It is the most common reason we take medicines. Until recently, however, most doctors knew of only a few drugs that stopped some pains. (48) But new knowledge about the process of pain Is helping them to control pain batter.
Scientists have learned that the sense of pain Is made up of both chemical and electrical signals. (49) Scientists also have learned that the nervous system sends two different kinds of pain messages to the brain: one very fast, the other slow.
The f

[填空题]Pain
All of us have felt pain. We have cut ourselves. We have been burned. Or we have had headaches. Some of us suffer pain rarely. (46)
Pain can take complete control of our body and mind, making it impossible to move and even to think. Yet we need pain. Without it, we would not know if we have hurt ourselves. It is our body’s warning system. (47)
Pain is the most common reason we go to a doctor. It is the most common reason we take medicines. Until recently, however, most doctors knew of only a few drugs that stopped some pains. (48) But new knowledge about the process of pain is helping them to control pain better.
Scientists have learned that the sense of pain is made up of both chemical and electrical signals. (49) Scientists also have learned that the nervous system sends two different kinds of pain messages to the brain: one very fast, the other slow.
The first message is the warning signal. It moves

[填空题]
All of us have felt pain. We have cut ourselves. We have been burned. Or we have had headaches. Some of us suffer pain rarely pain rarely. (46)
Pain can take complete control of our body and mind, making it impossible to move and even to think. Yet we need pain. Without it, we would not know if we have hurt ourselves. It is our body’s warning system. (47)
Pain is the most common reason we go to a doctor. It is the most common reason we take medicines. Until recently, however, most doctors, knew of only a few drugs that stopped some pains. (48) But new knowledge about the process of pain is helping them to control pain better.
Scientists have learned that the sense of pain is made up of both chemical and electrical signals. (49) Scientists also have learned that the nervous system sends two different kinds of pain messages to the brain: one very fast, the other slow.
The first me