问题
选择题
现有氨基酸700个,其中氨基总数为710个,羧基总数为708个。则由这些氨基酸合成的含有2条多肽链的蛋白质共有肽键、氨基和羧基的数目依次为[ ]
A.700、710、708
B.698、12、10
C.699、11、9
D.698、10、12
答案
答案:B
现有氨基酸700个,其中氨基总数为710个,羧基总数为708个。则由这些氨基酸合成的含有2条多肽链的蛋白质共有肽键、氨基和羧基的数目依次为[ ]
A.700、710、708
B.698、12、10
C.699、11、9
D.698、10、12
答案:B
阅读理解。 | ||||
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1. We can learn something about _________ from the form. | ||||
A. Programmes on TV B. Subjects of a school C. Dishes at a restaurant D. Films at a cinema | ||||
2. The programme "Animal world" is at _________. | ||||
A. 21:00 on Channel l B. 19:00 on Channel 2 C. 20:20 o0n Channel 2 D. 21:55 on Channel 1 | ||||
3. What's on Channel l at 21:15? | ||||
A. News. B. Foreign arts. C. China' 99. D. popular music. | ||||
4. The programme "English classroom" lasts _________ minutes. | ||||
A. 35 B. 30 C. 60 D. 20 |