计划生育中,常采用结扎输卵管的措施以达到避孕的目的,其原理是[ ]
A.使卵细胞不能受精
B.使精子不能进入子宫
C.使卵细胞不能形成
D.使雌雄激素不能分泌
答案:A
The tour guide finally managed to make the visitors ______ of the safety of the bungee jumping.[ ]
A. to convince
B. convincing
C. convinced
D. convince
善于治疗耳鸣、耳聋、头痛目赤的腧穴是()
A.外关
B.中渚
C.照海
D.翳风
E.支沟