虽然大家都知道要用不同时态，但其实就算是过去式，也有不同形态，混合使用才够高 级。将来时也是哦~
请比较以下句子：
1 I watched a film. It was interesting. (5.5分只有一种过去式)我看过一部电影，它很有趣
2 I used to watch movies every Saturday and one week I saw an interesting movie. (6.5分虽然都是过去式，但有两种形态，used to是个很重要的得分点)
请比较以下句子：
1 I saw a movie. It was interesting. I liked it. 我看过一部电影，很有意思，我喜欢它。(5.5分只有一种单一的过去式)
2 I always used to watch TV with my brother and I remember watching a TV show about an alien and I enjoyed it a lot. 我以前经常和哥哥一起看电视，我记得看过一部关于外星人的电视节目，很有趣，我非常喜欢。(7分两种以上时态，并且过去时态还进行了变换)
请比较以下句子：
1 How did you come here today?
I came here by bus.我乘公交车来的.(5.5分-只有一种过去式)
2 How did you come here today?
Well actually, I usually catch the tram, but today I was in a hurry, so I took the subway. 哦，其实平时我都坐公交车的，但今天时间紧，所以我乘地铁来的。(最好用tram来替代bus)(6.5分，现在和过去的混合)
