中低压玻璃钢管道堆放管材高度不应超过2m，直径在（）mm以上管材不得堆放。
参考答案：1400
Mary’s red face suggested that she_______shy, and her friends suggested that she______a deep breath.
A．be; should take
B．was, take
C．should be; took
D．was; takes
测量细菌大小的单位是（）。
A.μm
B.nm
C.mm
D.cm
E.m
