根据下列句子及所给汉语注释，写出空缺处各单词的正确形式。每空只写一词。

小题1:The exercises are designed to ________ (增强) your stomach muscle.

小题2:Don’t be frightened by the television camera. Just speak        (自然地).

小题3:The boy spoke in a low voice       （承认）that it was his fault.

小题4:Are you well __________(准备) for the entrance examination?

小题5:As the storm drew near, black clouds were __________ (聚集) over the sky.

小题6:However, his __________ (知识) of French remained very weak.

小题7:     (令人吃惊的是) , some graduates with qualification failed to find jobs.

小题8:The Bank of China has a lot of __________ (支行) in the world.

小题9:This kind of tree can only grow in the __________ (北方) parts of China. 

小题10:Nuclear physics is ________（超出） my understanding.