根据《倒置式屋面工程技术规程》5.1.4要求,当倒置式屋面坡度大于()%时,应在结构层采取防止防水层、保温层及保护层下滑的措施。
A.2
B.3
C.5
D.10
参考答案:B
He hasn't slept at all for three days. ____he is tired out.[ ]
A. There is no wonder
B. There is no need
C. It is no wonder
D. It is no way
施密特触发器具有()电压传输的特性。
A、超前
B、保持
C、滞后
D、稳态