输精管结扎术的手术步骤第五步为
A.卧床留观察2小时以上B.避免房事过度C.阴囊托D.避孕2~3个月E.避免重体力劳动为预防下列并发症,须采取上述哪项预防措施
参考答案:C
Email, as well as telephones, ________an important part in daily communication. [ ]
A. is playing
B. have played
C. are playing
D. play
桥壳的主要损伤是()、()、()及钢板座等处磨损。