如图1，△ABC和△DCE是两个全等的等腰三角形，BC，CE为底边．

一艘轮船以速度15m/s匀速运动，它所受到的阻力为1.2×10⁷N，发动机的实际功率是（　　）

Hello! My name’s John. I’m in Beijing now. It’s hot in Beijing. It’s sunny too.

I can wear my shorts and shirt. My shorts are green. I have a new jacket. My old jacket is too small. I want to buy a hat.The hat is very pretty, but it is $60. that’s very expensive.

The hat is cheap.

正在拉二胡的一位同学不断用手指去控制琴弦，这样做的目的是(    )。