控制疟疾症状发作的药物主要有__、__、__、__。
参考答案:氯喹;甲氟喹;青蒿素;奎宁
() is very convenient equipment for loading and unloading goods.
A. Crane
B. Pallet truck
C. Fork lift
D. Fork lift truck
曲柄连杆机构主要由()组成。
A.缸体
B.活塞、连杆
C.曲轴
D.油底壳
E.飞轮