There are many natural catastroophes occurring in nature.
自然界里有很多自然灾害发生。
I'd like to buy an excursion pass instead.
我要买一张优待票代替。
Yes, and we must stop people walking on this floor until it's firm. It may be necessary to put up a notice saying Keep off. Another thing, we' ll have to drill a hole in the wall for the electric wires.