单词填空：（注意使用其正确形式，每小题1分，共10分）
The witness _________________( 陈述 ) that he had not seen this woman before.
She returned from the vacation, feeling relaxed and _____________( 振奋 ).
He has made a great ________________( 贡献 ) to protecting the environment.
The _____________( 平均 ) income in my family is increasing.
He is full of _______________( 焦虑 )，for the exam is coming.
Tom was _________________( 任命 )  as Chairman of the Trade Union.
Prices are going up ________________( 平稳地 ) .
Don’t be ______________( 失望 ). Something good will come along sooner or later.
What are the harmful______________( 影响 ) of smoking ? 
Things can easily go wrong when people are under _________( 压力 ).