男性两侧输精管被结扎后,生理上表现为[ ]
A.不产生精子,第二性征不变
B.产生精子,第二性征改变
C.不产生精子,第二性征改变
D.产生精子,第二性征不变
答案:D
— I bought a very beautiful postcard for Teachers' Day.
— Really? When _____ you _____ it?
[ ]
A. do; buy
B. will; buy
C. did; buy
D. did; bought
分析各种风险的损失量属于()阶段的工作。
A.风险识别
B.风险评估
C.风险响应
D.风险控制