下列不是给实验小鼠进行编号标记的溶液是（）

A.3%～5%苦味酸溶液

B.2%硝酸银溶液

C.0.5%中性红溶液

D.甲紫溶液

E.伊红溶液

Hundreds of species are declared to _____ in the coming century.

A．die away

B．die out

C．die down

D．die off