截至2011年底，我国共有各种协会、学会、研究会、基金会、联谊会、联合会等各类社

根据句意和首字母或汉语提示完成单词。

1. A few readers are going to learn a f______ language.

2. Many v______ come to Rizhao for vacations every year.

3. Thanks for i______ me to your birthday party.

4. Sanya is in Hainan Province in s______ China.

5. Maria won first prize in yesterday's singing c______ 

6. It's going to rain. We should bring our ______ (雨伞).

7. Movie Palace has the most c______ (舒适)seats.

8. He bought some  ______ (礼物) for his friends when he went on the trip to the Yellow Mountains.

9. She ______  (观光) Asia when she was fourteen years old.

10. He ______ (借) some money from his mother and bought a book yesterday.

公允价值是指在评估基准日，自愿的买卖双方在知情、谨慎、非强迫的情况下通过公平交易资产所获得的资产的预期价值。( )

宿主龋齿非易感性表现在（）。

A.糖的摄入量多

B.氟的摄入量多

C.口腔菌斑量多

D.牙齿窝沟点隙多

E.漱口次数少

岩性孔隙度测井

交流电的特点是：电势、电压及电流的大小和方向都不断地随时间无规律的变化。