By that time the new system should be up and running.

　　到那時這個新系統應該會運轉起來了。

　　Many people feel that the law should be changed.

　　許多人都覺得這項法律應該修改。

　　The treatment should be repeated every two to three hours.

　　這種治療方法應該每隔兩到三小時重復一次。

　　I think we should go back to first principles.

　　我認為我們應該回到基本原則上。

　　You should not go out in the heat of the day.

　　你不應該在天最熱的時候外出。