小芳一般步长0.39米，她穿过球场要走92步，球场的长度大约是______米．
0.39×92，
≈0.4×90，
=36（米）；
故答案为：36．
设D是曲线y=x2与y=1所围闭区域，等于：().
A.A
B.B
C.C
D.D
So far, scientists haven’t found any evidence of water that ______ life on Mars.
A．holds
B．raises
C．brings
D．supports
等于：().
haven’t found any evidence of water that ______ life on Mars.