There is a system ________the waste is disposed of using the principles of ecology.

A．which

B．where

C．that

D．at which

从严重贫血儿童血中所得血红蛋白经水解后作氨基酸分析。下面哪一项一级结构的改变最可能与贫血表型相关

A．Gly-Asp-Gly变为G1y-Glu-Gly
B．Leu-Glu--He变为Leu-Val-Ile
C．Gly-lie-ely变为Gly-VM-Gly
D．lle—Leu—IVM变为11e-He-VM
K．Val—VM—V8l变为VMI~U-Vfl