A:One moment, please. I’ll see if there are any for tonight.
B:Sure. Please fill out this form for us.
C:Sorry. I’m afraid we have no one at this time
D:How long are you planning to stay here, sir?
在已知某小片段基因碱基序列的情况下,获得该基因的最佳方法是( )
下列各句中,没有语病的一句是( )
菱形ABCD中,∠B=60°,点E在边BC上,点F在边CD上.
(1)如图1,若E是BC的中点,∠AEF=60°,求证:BE=DF;
(2)如图2,若∠EAF=60°,求证:△AEF是等边三角形.