弱弱地问一句。。。这两句话地区别是神马

小黛安

(D) contain radioactive material that can be used to determine a sediment’s isotopic composition
(E) reflect the isotopic composition of the water at the time the shells were formed

glhelr

(D) contain radioactive material that can be used to determine a sediment’s isotopic composition
(E) reflect the isotopic composition of the water at the time the shells were formed

-- by 会员 小黛安 (2011/8/25 3:46:11)

有不同啊~
D选项说的是包含能反映沉淀物中构成。
E选项中说的是反映这个贝壳构成时水的iso构成~
简单说，一个说是沉淀物，一个说是水