题目

下列关于探究影响酶活性的实验中，能达成实验目的的是（ ） A . 以本尼迪特试剂作指示剂，用淀粉酶探究温度对酶活性的影响 B . 以本尼迪特试剂作指示剂，用淀粉酶探究pH对酶活性的影响 C . 用 H2O2酶探究温度对酶活性的影响 D . 用 H2O2酶探究 pH 对酶活性的影响 答案：D 完形填空。      A boy was walking home from school when he saw a large, tempting (诱人的) apple on one of the branchesof an apple tree hanging out over a tall fence. The boy wasn't much of a fruit-eater,   1   a bar of chocolate if given the choice,   2  , as they say, the forbidden fruit can be tempting. Seeing the apple, the boy wanted it. The more he looked at it, the   3   he felt and the more he wanted that apple.        4   as high as he could, but even as his tallest   5   he was unable to touch It. He began to   6   up and down,as high as he could, at the   7   of each jump stretching his arms to get the apple. Still it remained out of   8  .      Not giving up, he though, if only he had something to   9   on. His school bag wouldn't give enough height and he didn't want to  10  the things inside, like his lunch box, pencil case, and Gameboy. Looking  11 , he hopedhe might find an old box, a rock, or,  12  luck, even a ladder, but it was a tidy neighborhood and there was nothing he could use.      He had tired everything he could think to do.  13  seeing any other choices, he gave up and started to walk  14 . At first he felt angry and disappointed thinking about how hungry he had become from his  15 , and how he really wanted that apple. The more he  16  like this, the more unhappy he became.       17 , the boy of our story was a preetty smart guy,even if he cloudn't always get what get he wanted. He started to say to himself. This isn't  18 , I don't have the apple and I'm feeling miserable as well. There's  19  more Ican do to get the apple-that is unchangeable-but we are supposed to be able to  20  our feelings. If that's the case, what can I do to feel better? (     )1. A. preferring (     )2. A. so         (     )3. A. sadder    (     )4. A. expanding (     )5. A. strength   (     )6. A. jump       (     )7. A. tip        (     )8. A. hope       (     )9. A. put        (     )10. A. break      (     )11. A. up         (     )12. A. for        (     )13. A. Af ter     (     )14. A. back      (     )15. A. wishes     (     )16. A. thought    (     )17. A. Therefore  (     )18. A. skilful    (     )19. A. something    (     )20. A.change      B. offering  B. then       B. angrier    B. stretching      B. length      B. look       B. stage      B. hand       B. stand      B. shake      B. forword    B. with       B. Through    B. away       B. beliefs   B. imagined          B. However    B. cheerful   B. anything  B. express    C. receiving  C. but        C. hungrier  C. swinging  C. range     C. walk       C. top        C. sight      C. get        C. take       C. down      C. on         C. Without   C. up         C. efforts   C. tried      C. Moreover  C. harmful    C. everything      C. forget     D. allowing   D. or         D. tastier    D. pulling    D. height     D. glance     D. level      D. reach      D. hold       D. strike     D. around     D. of        D. Upon       D. down       D. goals      D. cliamed    D. Otherwise        D. helpful    D. nothing    D. describe