计算1080×20时，先用2乘（ ）得（ ），再在所得数的末尾添写（ ）个0。
108；216；两
简述肾素-血管紧张素系统对水盐代谢的调节。
—Well. I do think the rabbit is a beautiful, gentle animal which can run very fast.
— ________.
A．So it is
B．So is it
C．So does it
D．So it does
