雷达电缆头密封垫材料为（）。A.氟橡胶 B.天然橡胶 C.三元乙丙橡胶 D.丁腈橡胶

We ______ careful when we are walking across the road. There are too many vehicles now. [ ]

A. can be

B. may be

C. must be

控制疟疾临床症状的首选药物是

A．奎宁

B．氯喹

C．伯氨喹

D．青蒿素

E．乙胺嘧啶

What did he do a. He telephoned me. b. He picked up the phone. c. He put the receiver down. d. He put my hanger up.

胸部X线常见肺浸润，多发生肺脓肿、肺大疱和脓胸、脓气胸（）

A.毛细支气管炎

B.腺病毒肺炎

C.金黄色葡萄球菌肺炎

D.肺炎链球菌肺炎

E.肺炎支原体肺炎

男，20岁，3天前受凉后出现咳嗽、咳白粘痰，发热39℃，胸片示左下肺大片渗出影，予青霉素静点，如有效，则最先出现的是

A．胸片示片状阴影消散

B．咳嗽好转

C．体温降至正常

D．痰色转黄

E．痰量减少