My birthday is ______ May and his birthday is ______ March 26th.

The clever boy made a hole in the wall, _______ he could see _____ was going on inside house.

Who taught ________ to write the computer programs —Nobody. She learned it by __________.

You’d better choose someone____ you think ___ kind and friendly to help you.

It was ______ he does ______ makes his students enthusiastic about school.[ ]