No,it isn't.

不，不是。

I'm thinking about my lesson.

我正在考虑课程。

While you were writing letters,I was reading a book.

当你正在写信时，我正在读一本书。

Should I go this way,or that way?

我应该这样去,还是那样？

Of course I want to know what your opinion is.

当然我想要知道你的意见是什么。

Please call before you come,otherwise we might not be home.

请在你来前打一下电话来,否则我们可能不在家。