题目内容：

I have been to Beijing before.______
A So do i B SO had i C SO have i D SO did I

优质解答

C表示说话者也适用上述情况,用so + be/have/has/情态动词+主语答句可转换成：I have been to Beijing before, too. 故用have若此题改为：I had been to Beijing . 答句用SO had i (=I had been to Beijing, too.)若...