She is very nice, but because she has a（）way of speaking, she is slow in making friends

I don't know who on（）stole the diamond last night.

Nobody knows how long and how seriously the shakiness（不穩(wěn)定） of big businesses will （） down the economy.

Mr. Edward was not in, so his brother acted as （）at the party.

An explosion is a sudden increase in amount（）