There are fifty students in our class. 30% of them are girls. _____ of them are boys.

I’m not free today Let’s make it ____ [ ]

The chair is broken．Please ________ who broke it．

In many ways China’s rapid growth has been seen as a ______ to improve thecooperation with other countries.

I think it takes a lot of practice to play the violin well.— . Practice makes perfect.