下列关于还原型谷胱甘肽的叙述，错误的是

A．含有一个巯基

B．含有两个肽键

C．Glu的α-羧基参与肽键形成

D．它是体内重要的还原剂

All the people present were _____ at the _____ news. [ ]

A. shocked; shocking

B. shocking; shocked

C. shocked; shocked

D. shocking; shocking