愚教授，你这typo也太多了吧！

The body of （an） animal is like a mahcine such as an train engine.

oxygen gas

a digestive tract, which intakes and absort （absorbs） foods， organs which discharges waists

and legs or wings on (with) which the aninmal move（s）.

所有跟帖： 

• discharge waist？？？哈哈，愚教授，乐死我！！！ -beautifulwind- ♀ (0 bytes) () 08/10/2011 postreply 23:44:18

• 还不是的i999的pp害的。 -EnLearner- ♀ (99 bytes) () 08/11/2011 postreply 00:02:31

• LOL. -EnLearner- ♀ (226 bytes) () 08/10/2011 postreply 23:59:38