Usually a house is too expensive for the salary-earning class to buy.
通常房屋太贵,工薪阶层买不起。
Don't be anxious if I'm late.
如果我回来晚些也不必担忧。
In this part of the cave, they could hear an insistent booming sound which they found was caused by a small waterspout shooting down into a pool from the roof of the cave.