电器设备发生火灾事故时，应该用（）灭火器扑灭火灾。
A.干粉灭火器
B.酸碱灭火器
C.泡沫灭火器
参考答案：A
The （）were carefully inspected before we issue the Phytosanitary Certificate.
A．animal products
B．plant products
C．machines
D．electronic toys
A survey was carried out on the sleep time of students in middle schools, ______ were surprising.
A．its results
B．whose result
C．the results of which
D．of which results
