如图所示是电热吹风机的电路图，要使它吹热风，则其联动开关应连接
A．1与2
B．2与3
C．3与4
D．无法确定
答案：C
The table is too big and it almost half of the room.
A．takes away B．takes off C．takes up
急性牙髓炎最有效的应急处理是
A．局部麻醉
B．开髓引流
C．服止痛药
D．针灸止痛
E．消炎止痛
