晶体管电动汽油泵的控制电路是一个()电路,工作时使通过主线圈的()电流,产生的磁场作()变化,从而控制机械油泵部分工作。
参考答案:自励间歇振荡;时通时断;周期性
Only after they had discussed the matter for several hours ______a decision.
A.they reached
B.did they reach
C.they reach
D.do they reach
羌活与独活的功效共同点是
A.解表散寒,止痛,祛风湿B.祛风胜湿,活血止痛C.祛风散寒,舒筋活络D.祛风除湿,化湿和胃E.祛风湿,止痛,利水