6.Three million tons of coal ______ every year in the city.

Three million tons of coal ______ every year in the city.
A.is exploited
B.are exploited
C.had exploitedx05
D.have exploited
答案：B
解析：coal用ton量词来修饰,Three million tons 为复数,所以谓语动词为复数.
中文：在这座城市每年都会开发出三百万吨煤.

我认为对
这个城市每年有三百万吨煤被开采。
这里三百万吨是复数。