木工钻床又成为打眼机,按其外形可分为()两种。
A、厢式
B、柜式
C、立式
D、卧式
参考答案:C, D
Jane’s pale face suggested that she ill and her mother suggested that she be sent to hospital
without delay.
A.be
B.should be
C.was
D.is
利用光电效应的传感器属于结构型光电传感器。