* * 粘膜由____________所覆盖，通过 * * 脱落细胞检查和观察宫颈粘液的变化，可以了解_________功能。
参考答案：复层鳞状上皮；卵巢
Robert is said________ abroad, but I don’t know what country he studied in.
A．to have studied
B．to study
C．to be studying
D．to be studied
钢材两种破坏现象和后果是什么？
