屋面刚性防水层施工环境气温宜为0～35℃，并应避免在负温度或烈日暴晒下施工。( )
参考答案：错
Last summer holiday, I went back to my hometown, _______ the neighbors and the house _____ I used to be familiar with were gone.
A．only finding; which
B．only found; that
C．to find; whom
D．only to find; that
（）是指如果线网可以吸收能量，例如线网电压最高限额还没达到，制动能量可以反馈至线网。
A.气制动
B.电阻制动
C.常用制动
D.再生制动
