A:
B:
C:
D:
计算:abc•c2a2的结果是( )
如图,a、b是一点光源S射向凸透镜的两条光线.下列说法正确的是( )
⑴Your school is great. ____ A. See you later.
⑵How are you?____ B. It's a new school.
⑶Goodbye!____ C. I can show you.
⑷Excuse me, where is the shop?____ D. Thanks.
⑸What is it?____ E. I'm fine. Thank you.