try to understand ________ that prevents so many children from being happy, there seem to be three causes.

104. My uncle was still on the_______ leave at home.

I think 20 dollars for it is OK.—No,I’d gladly pay for it.

Theprogram was so fascinating that the children kept their eyes _____on the screen

－What’s wrongwith Tom He didn’t talk to allthe afternoon.－Oh, he failedin his exam.