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