用所给单词的适当形式填空。

1. It’s important for children to learn about road ______(safe).

2. To prepare for the match, they receive two hours’ ______ (train) every day.

3. The ______ (France) are famous for their cooking.

4. Such after-school activities as sports clubs and language ______ (society) are usually popular.

5. He was late, but ______ (fortunate) the meeting hadn’t started.

设有图书管理数据库：
图书(总编号C(6)，分类号C(8)，书名C(16)，作者C(6)，出版单位C(20)，单价N(6，2))
读者(借书证号C(4)，单位C(8)，姓名C(6)，性别C(2)，职称C(6)，地址C(20))
借阅(借书证号C(4)，总编号C(6)，借书日期D(8))
对于图书管理数据库的读者表，为工资属性增加有效性规则(工资大于等于0)和出错提示信息(工资应该大于等于0!)。请对下面的SQL语句填空：
ALTER TABLE读者ALTER工资；
______