按照所学课文根据首字母、汉语提示填空，每空限填一词（共10小题；每小题0.5分，满分5分）。
It is important to keep c       in time of danger.
I said hello to her, but she i      me completely and walked on.
Although Tim and Mike came from e       different backgrounds, they
became close friends.
His mother is ill. He is c       about her health.
Mandela took an a       part in the struggle for independence.
In that big fire all their houses were completely         （毁了）, so they had to build new ones.
The new model sells well because it is of good         （质量）and the price is low.
Please remember as many words and          (词语、表达) as possible.
The president made an          (正式的,官方的) visit to China last month.
The famous film star wore a pair of large sunglasses so that people wouldn’t          （认出）her．