题目内容：

单句改错 （共5小题; 每小题1分，满分5分）

此题要求改正所给句子中的错误，每句只有一处错误，必须按下列要求改正：

该行多一个词：把多余的词用斜线（\）划掉。

该行缺一个词：在缺词处加一个漏字符号（∧），在下面写出该加的词。

该行错一个词：在错的词下划一横线，在下面写出改正后的词。

 

1. Last night, his father came back late as usually.

2. At the end of 16^th century, about five to seven million people spoke English.

3.The Mekong River becomes rapids as it passes across deep valleys.

4.This is the reason why she explained to me just now.

5.The boss requested that all the work must be finished as soon as possible.