A、<img width="13" height="38" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/e7e3eb75-a80b-4225-8f37-f2cd795832f9.png" />
B、<img width="14" height="35" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/74ff6a18-06c9-4e57-b06a-2e17cc662cf9.png" />
C、<img width="14" height="35" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/0c0ef704-4326-4e28-a725-8f36e6c129a5.png" />
D、1