语法填空(共10小题；每小题l 5分．满分l5分)

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卡标号为16—25的相应位置上。

The Dragon Boat Festival is celebrated on the fifth day of the fifth month according to the Chinese calendar. For thousands of years, the festival _小题1:________ (mark) by eating zong zi and racing dragon boats in honour of Qu Yuan, who is said to have committed suicide(自杀) by drowning himself.

Qu was a minister of the State of Chu ____小题2:___ (situate) in the present-day Hunan and Hubei provinces, during the Warring States Period（战国时期）. He was upright, loyal and highly respected. ____小题3:__, he was dismissed from office. __小题4:____ (realize) that the country was in the hands of evil officials, Qu leapt into River Miluo on the fifth day of the fifth month. Nearby fishermen rushed over to save him but were ___小题5:____ (able) to recover his body.

The people of Chu __小题6:___ mourned Qu’s death threw rice into the river to feed his ghost ___小题7:___ year on the day of his death. But one year, the spirit of Qu appeared and told the mourners that a huge reptile（爬行动物）in the river had stolen the rice. The spirit then advised __小题8:_____ to wrap the rice and bind it _小题9:____ throwing it into the river.

During the Duanwu Festival, zong zi is eaten to symbolize（象征，表示） the rice offerings to Qu. And the dragon-boat races symbolize __小题10:_____ many attempts to rescue and recover Qu's body.

用含32P的磷酸盐的营养液培养动物细胞，一段时间后，下列构成线粒体的哪些结构或化合物不具有放射性（）

A.脱氧核糖

B.线粒体内外膜

C.RNA

D.线粒体基质