题目内容：

Complete the sentences with the given words in their proper forms（用括号中所给单词 的适当形式完成下列句子)

1.Helen lives on the     floor of this tall building.(twelve)

2.As a teacher, Mrs.Green always speaks     to the children.(slow)

3.I don’t think Tom can swim     the river at this point.It’s too wide.(cross)

4.My grandparents say that regular exercise and a good diet can     years to life.(addition)

5.Many students in Shanghai go to America for     study every year.(far)

6.George is measuring the      of his computer desk to see if it will fit the new study.(long)

7.If you don’t go on a diet, it is      for you to lose weight.(possible)

8.The     served us so wonderfully that we thanked her again and again.(wait)