A:You're welcome.
B:That's right.
C:It's hard to say.
▱ABCD中,∠A比∠B小20°,则∠A的度数为( )
王老师布置了一项研究新文化运动的作业,如果是你来完成,你会参考哪一报刊?( )
I'm not sure whether I can hold a party in the open air, because it ________ the weather.
用显微镜观察小鱼尾鳍内血液的流动时,辨别毛细血管的依据是( )