使用简短的，主动态的句子。

Use short, active voice sentences.

youdao

当他来这里时，我们正在学习英语。（过去进行时主动态）

When he came have, we were studying English.

youdao

（现在完成时主动态）从那时以来，我们保持联系已有相当长的时间了。

Since then we have kept in contact with each other for quite a long time.

youdao

他对此一无所知，没有人跟他商讨过这样计划。(加上“人”变主动态)。

He had no knowledge of this and had not been consulted on these plans.

youdao

目的研究主动脉弓动态图像测量的方法。

Objective to research a dynamic image measurement approach to aortic arch.

youdao

目的研究主动脉弓动态图像测量的方法。

Objective to research a dynamic image measurement approach to aortic arch.

youdao