______ you study hard, you will pass the exam.

It is believed that if a book is ______, it will surely ______ the reader.

Helen was much kinder to her youngest son than to the others, __________, of course, made the others envy him.

—I think languages subjects are more interesting than science ones. —________. I prefer science subjects. 

The two boys look _______ much alike _______ no one can tell them apart.