求解决英语速求!急!把以下句子转成主动语态

Books of this kind sell well.

Great changes have taken place in our hometown in recent years.

To make our city cleaner and more beautiful,rubbish musten not be thrown about in public places.

Your pronunciation must be aid attention to.

Not yet.I will finish it if I am given ten more minutes.

Twelve students in that school were sent abroad to study medicine last year.

In many places of China,tne old people are taking good care of not only by their family but aiso by the local governments.