说者用 they could ,不用 were able to 并不是不能用,他只是没有做那个选择,
下面两个句子的含义其实是一样的:
Firemen had been fighting the forest fire for nearly three weeks before they could get it under control.
Firemen had bee...
说者用 they could ,不用 were able to 并不是不能用,他只是没有做那个选择,
下面两个句子的含义其实是一样的:
Firemen had been fighting the forest fire for nearly three weeks before they could get it under control.
Firemen had bee...