A:C5H12
B:C4H10
C:C3H8
D:C2H6
由曲线y=x2-2x与直线x+y=0所围成的封闭图形的面积为( )
⑴How many pears do you see?____ A. OK.
⑵Let's read a book.____ B. I have 20.
⑶Look at my new toy car.____ C. Oh, how beautiful!
⑷How many eggs do you have?____ D. I see 12.
⑸Can you count with me?____ E. Sure. 1, 2, 3. . .
人体每天摄入800克食物和1200毫升水的情况下,消化腺大致分泌1500毫升唾液、2000毫升胃液、1500毫升肠液、500毫升胆汁、1500毫升胰液.据此可以判断消化道中消化液最多的是( )