will与 be going to do 和be to do和be about to do 和be doing有什么区别?在写句子时都可以用吗?

1.will+动词原形，。
就是表示一般将来时。。这个比较常用

2.be going to do
将会...
一般用于将来时态

例句与用法:
1. I am assuming that the present situation is going to continue.
我认为目前的情况将会继续下去.

2. It's going to cost 200 or as near as dammit.
这要花200英镑上下.

3. How did you find out that Burns was going to be promoted?
你是怎么知道伯恩斯将会得到提升的？

4. You must be out of your mind if you think I'm going to lend you 50!
你以为我会借给你50英镑, 你准是疯了!

5. I'm just going to check in these books at the library.
我要去图书馆还这些书。

6. They are going to move to a new house next week.
下星期他们将迁入新居。

7. It looks as if it is going to rain.
看来要下雨了。

8. Are you going to America by boat or by plane?
你到美国是坐船还是坐飞机？

3.be to do

表示安排、计划、决定、命令或注定要发生的事.
一般用于被动语态，，，to be done
也可以用于主动语态。。。都是表示将来时态

比如：
Greater efforts to increase agricultural pro