维系蛋白质一级结构的化学键为 （ ）
A．氢键
B．肽键
C．疏水键
D．离子键
E．配位键
参考答案：B
It’s a pleasure to watch the face of a _____ baby.
A．sleeping
B．asleep
C．slept
D．sleep
A Web （ ） is one of many software applications that function as the interface between a user and the Internet.
A．display
B．browser
C．window
D．view
