题目内容：

根据句意，用括号内所给单词的适当形式填空。

1.The problem is so easy that I have no difficulty        (explain) it to my classmates.

2.If you tell him the            (true)，he will be angry.

3.You may ask your teacher for help. He will give you a few        (value) suggestions.

4. People in the past suffered from hunger and         (ill).

5.I invited Sally to my party, but she refused         (accept) my invitation.