1.before 改为 ago ,a改为an
2.while改为when
3.book改为books
4.hardly改为hard
5.been去掉
6.will改为would,help前面加to
7.unless改为if
8.encourage改为encouraged
9.not去掉
1.before 改为 ago ,a改为an
2.while改为when
3.book改为books
4.hardly改为hard
5.been去掉
6.will改为would,help前面加to
7.unless改为if
8.encourage改为encouraged
9.not去掉