单词拼写。（共10小题，每小题1分，满分10分）
Many teenagers are                 (疯狂的) about online games.
They have tried all sorts of                  (治疗) for her disease but without success.
Police suspect there may be a                 (联系)between the two murders.
With this extra evidence he was able to                   (宣布) with certainty that polluted water carried the virus.
The volunteers                   (贡献) huge amounts of their time to the project.
Our children                   (参加) the same school.
It is a pity that the industrial cities built in the nineteenth century do not            
（吸引）visitors.
How many groups are the students in your class               (把…分成) into?
She                (折叠) the letter and put it into the envelop.
This is a mixture                   (由…构成) of flour and water.