The boy’s ______ expression on his face suggested that he must have met across something______.[ ]

Why not_______ an English club to practice _______English

A pen is on the right of a ruler. The ruler is on the right of an eraser. That is to say, the ruler is ______ them.

So difficult ___it to work out the problem that I decided to ask Tom for advice.

_______ did you stay in America— For about two weeks.