维持蛋白质基本骨架的是
A．共价键 B．氢键 C．高能键 D．磷酸二酯键 E．肽键
参考答案：E
—Where is Sally from , Mike ? —
A．I am from China.
B．She is from America
C．He is from England
D．You are from Japan
什么是干燥？
