补全对话。
Anna: ____.
John: ____. Can I have a look?
Anna: ____. Here you are.
John: ____.
John: You are welcome.
A. Sure!
B. I have a nice cat.
C. Oh, really?
D. Thank you.
E. Oh! It's nice. I like it.
空间四边形ABCD的对角线AC=8,BD=6,M,N分别为AB,CD的中点,并且AC与BD所成的角为90°,则MN=( )
美国史学家斯塔夫里阿诺斯认为,“对列宁来说,新经济政策并不意味着社会主义在俄国的结束,而是暂时的退却。”“暂时的退却”是指( )
—Can your mother play chess? —______________.