Following the girl, we went into a hall, on ____ walls hung a few pictures of some famous scientists．

The teacher agreed to the suggestion that the students ________ two weeks to prepare for the exam.

He has been working hard day and night, which, of course,his tiredness.

Let’s ______ each other．

A nature reserve for white-flag dolphins was set up in 1992, _______ boats have beenprohibited from sailing around since then