雌激素的生理作用,不正确的是()
A.使子宫发育
B.促进水与钠排泄
C.促进输卵管发育
D.促进骨中钙的沉积
E.促进 * * 上皮细胞的增生
参考答案:B
The old man lives ____ in the countryside, but he doesn’t feel_____ because he chats with his children on the Internet every night.
A.alone; alone
B.lonely; lonely
C.alone; lonely
D.lonely; alone
定向井在0°~45°时最好选用()。
A、层流
B、紊流
C、柱流
D、任意