题目内容：

单词拼写。（共6题，计6分）

1.Polluting the environment is a danger to the ______________ [sə'saɪəti]

2.He ____________ [dɪ'vaɪdɪd] his class into four groups to practice playing basketball.

3.He worked so hard that he without _________________ [daʊt] is the winner in the exam. .

4.___________ ['enəmɪz] can be turned into friends.

5.What does Lucy usually do in her ________________ [speə(r)] time?

6.He was __________ [nɒkt] down by a car yesterday.