脯氨酸和羟脯氨酸与茚三酮的反应产物呈（）色，其余α-氨基酸与茚三酮反应生成（）色产物。
参考答案：黄；蓝紫
---_________ she can’t find her keys? She’ll be locked out all night.
---You are right. I’d better call her to check if she’s OK.
A．What about
B．What with
C．What if
D．What for
设计中对空载率大于（）的电动机和电焊机，可安装空载断电装置。
A.25%
B.70%
C.50%
D.85%
