______ is impossible if you put your heart into it. 

Some students are playing football. _______are doing their homework.

Boys, don’t lose____ in playing Angry Birds. It is bad for your eyes to play computer games for a long time

Roy made several kites, but _____ of them can fly high in the sky.

–I like English best. What about _______?–He thinks science is very interesting. His favorite subject is science.