咖啡因的特征反应是()
A. Vitali反应
B. 绿奎宁(Thalleiaquin)反应
C. Marquis反应
D. 紫脲酸铵反应
E. 双缩脲反应
Tom seldom goes out. He is so____!
A. angry
B. weak
C. small
D. thin
You are too slim and you have to____weight.
A. put up
B. get on
C. put on
D. go on
Have you done something____today.
A. slow
B. special
C. simple
D. short