深秋晴朗的夜晚，农民常用熏烟的方法来防止霜冻，主要原因是[ ] A、浓烟散射地面

Elaine Wu is part of the first generation (代) of Chinese pianists. Born in Shanghai, she began practicing the piano at the    小题1:  of six when she was found to show a strong interest in classical music and the piano. One year later, she w 小题2:  the first prize at a children’s piano competition in Shanghai.

A 小题3:  winning the prize, she went on to study under the    小题4: (著名的) Italian musician and piano educator Maestro Mario Paci. She had put all her energy into her music career in the    小题5: (过去) eighty years.

She put on performances at home a 小题6:  abroad. In 1962, she was regarded    小题7:

the national first-class pianist.

In 1993, Wu was    小题8: (邀请) to teach piano in Singapore. She has been living t 小题9: ever since. In August 2013, her    小题10: (第二) album (专辑), A Generation of Master 2, came out with full support from her fans.

下列何组均是放射性核素（）

A.1H和2H

B.1H和3H

C.2H和3H

D.1H、2H、3H

E.3H和32P

当事人应如何查询自己的婚姻登记档案？

放疗后多长时间内，照射野骨放射性浓聚增加（）。

A.1小时～5天

B.10～15天

C.20～30天

D.45天～3个月

E.大于6个月

声音在水中的传播速度约为（）

A.340m/s

B.1500m/s

C.330m/s

D.1400m/s