小蓝P273 （128）

As a result of the ground-breaking work of Barbara McClintock, many scientists now believe that all of the information encoded in 50,000 to 100,000 of the different genes found in a human cell are contained in merely three percent of the cell’s DNA.

(A) 50,000 to 100,000 of the different genes found in a human cell are contained in merely
(B) 50,000 to 100,000 of the human cell’s different genes are contained in a mere
(C) the 50,000 to 100,000 different genes found in human cells are contained in merely
(D) 50,000 to 100,000 of human cell’s different genes is contained in merely
(E) the 50,000 to 100,000 different genes found in a human cell is contained in a mere

我选了D，答案选E。我有2个疑问：1，为什么是the 50,000 to 100,000而不是50,000 to 100,000；2， 为什么是in a mere而不是in merely 。请大家帮忙分析下，谢谢。