问题
单项选择题
有关维生素C特性的描述，错误的是
A．水溶液中易氧化
B．遇热不稳定
C．碱性溶液中极易破坏
D．还原型与脱氢型都有生物活性
E．可使羟脯氨酸、羟赖氨酸转化为脯氨酸、赖氨酸
答案
参考答案：E
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有关维生素C特性的描述，错误的是
A．水溶液中易氧化
B．遇热不稳定
C．碱性溶液中极易破坏
D．还原型与脱氢型都有生物活性
E．可使羟脯氨酸、羟赖氨酸转化为脯氨酸、赖氨酸
参考答案：E
| 完形填空。 | |||
| I found a boy sitting down beside me on the seat and watching the cars go past. He had a little book and a pencil. When a car_____ (1), he wrote something in the book. He didn’t take any_____ (2) of buses or vans, but only cars. Of course, it was none of my business, but I still wondered_____ (3) he was writing. I am very interested in jobs that some people have. So after a few minutes I said, "You’re very interested in the cars. May I ask what you’re writing in your book?" He answered, “I’m writing_____ (4) the numbers on the cars." "Oh I see. Is that your job, or are you just doing it for_____ (5)? When I was your age, I collected train numbers…" He laughed, “I have a better reason_____ (6) that," He said. “You see, every car has its own number, and each number is different from_____ (7). I discovered the fact five years ago, but it isn’t widely known. Well, I’m thinking of buying a car myself, and my number must be different from all the others,” he smiled then and quickly_____ (8) the number of a passing car. It was 68357. He said, “Can you answer an important question for me?" "Yes, if I happen to know the answer. Please go ahead." "What’s the highest number a car can have in our country?" I thought for a minute and then said, "I believe it will be 99999. Now new cars have numbers that____ (9) a 6, like that one." I pointed to the 68357 in his book. He looked thoughtfully. "I’ve got a long way_____ (10) then, if 99999 will be highest. I’ve got only forty-six thousand numbers so far. I’ve already finished three books and almost this one, but I still can’t find my number yet." | |||
| ( )1. A. passed by ( )2. A. looks ( )3. A. that ( )4. A. on ( )5 A. money ( )6. A. to ( )7. A. others ( )8. A. put down ( )9. A. begin with ( )10. A. going | B. went up B. lots B. which B. out B. playing B. with B. the others B. put up B. begins with B. walking | C. come over C. notice C. who C. down C. practice C. of C. all others C. put off C. beginning with C. to go | D. went away D. care D. what D. in D. fun D. than D. each other D. put on D. begun with D. of going |