你怎样向你父亲介绍自己的朋友Amy?_____。
A:This is my friend, Amy.
B:He is Amy.
C:This woman is Amy.
使用显微镜观察某一细胞时,选择下列哪种组合所观察的物像最大( )
①5错误目镜 ②10错误目镜 ③10错误物镜 ④40错误物镜.
——Though radio and television are ____ popular in the world today, I think the TV is ____ useful.——Of course, on TV we can see and hear what is going on home and abroad.