A、<img width="100" height="21" src="http://admintk.100xuexi.com/UpLoadImage/2016-10-26/dd35c105-5648-4c22-af8f-2bfde4372ec2.png" />
B、<img width="101" height="21" src="http://admintk.100xuexi.com/UpLoadImage/2016-10-26/52b925b2-1f0d-4248-b08f-1a533b5be810.png" />
C、<img width="101" height="21" src="http://admintk.100xuexi.com/UpLoadImage/2016-10-26/497eab22-1c06-428d-aab4-dbe5c5f6f298.png" />
D、<img width="101" height="21" src="http://admintk.100xuexi.com/UpLoadImage/2016-10-26/ea67bbf6-c948-411c-844a-6fc013b99058.png" />