读诗《青松》根据意思写诗句。

还要等到大雪融化的时候。____

青松仍然是直的。____

在证明“在△ABC中至少有两个锐角”时，第一步应假设这个三角形中（　　）

    Do you know about the U．K.? London is the capital city. Its flag is red, white and blue.They speak English. Big Ben is very famous. Kings and queens live in palaces. I have an uncle. He lives in London.He says, "London is clean and beautiful."He is a teacher. He works from Monday to Friday.On Saturdays and Sundays, he likes to play football and go for a walk. I want to go to the U．K. Because I want to see Buckingham Palace.

⒈____ ⒉____ ⒊____ ⒋____ 

物体m从倾角为α的固定的光滑斜面由静止开始下滑，斜面高为h，当物体滑至斜面底端时，重力做功的功率为（   ）