A、<img width="57" height="39" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/2f02acbc-25b7-44fe-8fc5-e13aa63c85b9.png" />
B、<img width="60" height="40" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/0b3bf53f-7127-4eb8-ad9c-4540b1470b3b.png" />
C、<img width="59" height="40" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/8ea9c2f8-50e3-4b04-81e0-a5b0a15429ba.png" />
D、<img width="48" height="37" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/92cae87c-067c-4276-8da1-2dc2eb56dd45.png" />