有一读者问： 有这样一道填空题：
(1)Tons of rubbish_________ （be）being taken out of the city center.
应填is还是are?
一般说来，如不强调tons， miles, metres等, “tons， miles, metres等+ of +不可数名词”之后皆应用单形动词，再如：
(2)Tons of low-radioactive waste was actually the debris of a cement floor which had been contaminated with tiny amounts of uranium.
(3)Miles of red ribbon, cardboard banners, cowboy rope and tractors was used to fill in the gaps in barren, sunscorched stretches of the southwest.
(4)In 1986, 5 million square metres of new living space was built in the capital.
