The Sydney Opera House is like a huge sailing boatwith water ____ three sides.

You should be _______ careful when you take the chemistry exam.—- I agree. In this way, I will make _______ mistakes.

He commanded that the students ______ the classroom before he returned.

What about_______ a rest—OK! Let’s go for a walk.

t not been for my teacher’s help, I the first place in the contest.