单复数的问题~~~

oo1x1oo

Some scientists have been critical of the laboratory tests conducted by the Federal Drug Administration on the grounds that the amounts of suspected carcinogens fed to animals far exceeds those that humans could consume
A. far exceeds those that humans could consume
B. exceeds by far those humans can consume
C. far exceeds those humans are able to consume
D. exceed by far those able to be consumed by humans
E. far exceed those that humans could consume
想问一下是说amounts是复数吗？

oo1x1oo

是不是加s的一般就是复数呀。。。。在GMAT里

zxkingsey

是复数
不是加S的都是复数
statistics就不是复数