一个教室房顶的面积大约为100m2,在一个标准大气压下,房顶受到向下的压力大约是______N.
F=PS=1.0×105Pa×100m2=1×107N.
故答案为1×107.
Is your brother going to to America? [ ]
A. visit
B. arrive
C. travel
D. meet
1.25×35.7×32×25=( )
A.35700
B.3570
C.5240
D.52450