用英语怎么说?不难,初3地

1.There__once___be a big free in front of our classroom. once:曾经.
2.She ___introduced____her friend yesterday. introduce,及物动词.
3.The girl seemed to do these things___on purpose____yesterday.
on purpose:adv. 故意. 还有,deliberately(adv.)也是故意的意思
4.I'm very busy___now___and can't speak to you. 结合语境.

我们教室前曾经有棵大树?
There_used__be a big free in front of our classroom
昨天,她把我介绍给了她朋友.
She __introduced me to_____her friend yesterday
这个女孩好象故意做这些事情.
The girl seemed to do these things__on purpose_____yesterday.
现在我很忙,不能和你说话.
I'm very busy__at this very moment____and can't speak to you

怎么觉得这些句子这么别扭？

There_is__be a big free in front of our classroom
She ___introduced____her friend yesterday
The girl seemed to do these things___on purpose____yesterday
I'm very busy___now___and can't speak to you

1. used to
2. introduced me to
3. on purpose
4. at