完成句子.（共6小题;每小题1分,满分6分）
The headmaster __________ (宣布) that we would put off the sports meeting because of the weather.
Old people should be _________ (说) to politely.
Of all the __________ (发明)，which do you think is the most useful?
We’ve had several____________(分歧)，but we still get well on with each other.
I like to sing songs while  _________ a shower.( 淋浴)
.His health is___________(逐渐) improving.