试题题干
Correct one error in each of the following sentences.
He could swim half way before he collapsed.
参考答案
试题解析
表示过去通过努力终于做成了某事要用be able to，而不能用can。
句意：他能游到一半才倒下。
Correct one error in each of the following sentences.
He could swim half way before he collapsed.
表示过去通过努力终于做成了某事要用be able to，而不能用can。
句意：他能游到一半才倒下。