如图,四边形ABCD的对角线AC、BD相交于O,且将这个四边形分成①、②、③、④四个三角形.若OA:OC-=0B:OD,则下列结论中一定正确的是 ( ) A.①与②相似 B.①与③相似C.①与④相似 D.②与④相似
I still don' t know what____ while I was away from home.
You'll know it all some day, l believe.( )
A.had happenedB.would happen
C.has happenedD.happened
My sister______ the piano very well, but she hasn't had time to play recently.( )
A.will playB.has playedC.playedD.plays
It's very kind of you to help me. Thank you very much.
______.( )
A.Thank you
B.Don't thank me
C.Sorry to help you very little
D.You are welcome
How is the young man?
_____________.( )
A.He's twentyB.He's much better
C.He's a doctorD.He's Mr Smith
Hello, haven' t seen you for a long time! You look fine!
________________( )
A.Oh,noB.ThanksC.GreatD.Not at all