关于四大高原的叙述，正确的是（　　）

　　根据短文内容，判断下列句子的正误 。

A

       If someone asks me, “Do you like music?”I'm sure I will answer him or her” Of course, I do.” Because I think music is an important part of our lives.

　　 Different people have different ideas about music. For me, I like rock music because it's so exciting. And my favourite rock band, the” Foxy Ladies (酷妹) “is one of the most famous rock bands in the world. I also like pop music. My classmate Li Lan loves dance music, because she enjoys dancing. My best friend, Jane, likes jazz music. She thinks jazz is really cool.

     “I like dance music and rock very much，”says my brother,“because they are amazing.”

　　But my mother thinks rock is boring.“I like some relaxing music，”she says. That's why she likes country music, I think.

如图所示，沿斜面向上拉一个重为4.5N的物体到斜面顶端，斜面长1.2m，高0.3m，拉力做功为2.16J，则这个斜面的机械效率是____%，物体受到的摩擦力是____N．