should 主要用来说对的或有理性.如：Children shouldn’t be allowed to play in the street.
be supposed to 可表示
1.预期或意图要发生（尤其是实际未发生）如：
The meeting was supposed to take place on Tuesday, but we’ve had to postpone it.
2.很多人认为是真的（可能不一定）如：
Mrs Carver is supposed to have a lot of money.
3.应该,这时跟should很接近,但是主要是指从规则,或是权威人所说的话方面.实际上往往应该翻译成“得”或“必须”.如
We’re supposed to check out of the hotel by 11 o'clock.
