问题
选择题
—What are you doing?
—I _________ my classmates.[ ]
A. watch
B. watching
C. am watching
答案
答案：C
搜题请搜索小程序“爱下问搜题”
—What are you doing?
—I _________ my classmates.[ ]
A. watch
B. watching
C. am watching
答案：C
类药物的催眠作用机制是（）