单词拼写（每小题1分，共5分）
It is a p______ that the weather is so bad today. We can’t go to a picnic.
You should always knock at the door before you e______ a room.
It is p_______（礼貌的）to offer seats to the old on the bus.
When swimming, you should put s_______（安全）first.
The newly-opened museum is certainly w_______（值得）a visit.