立克次体的主要代谢底物是()
A.苯丙氨酸
B.谷氨酸
C.赖氨酸
D.鸟氨酸
E.天冬氨酸
参考答案:B
解析:谷氨酸是所有病原性立克次体重要的代谢底物。
句型转换
1. It's Wednesday today. (对划线部分提问)
______ ______ ______ ______ today?
2. It's ten o'clock now. (对划线部分提问)
______ ______ ______ ______ now?
3. They do their homework in the evening.(改为否定句)
They ______ ______ their homework in the evening.
4. Let's go to play football. (改为同义句)
______ ______ going to play football?
5. have, lesson, at, two, I, a, chemistry, half, past
(连词成句)
_____________________________________________________
如何测定机械效率?适用于汽油机的是哪种方法?为什么?