A:left home, is
B:been away from home, is
C:left home, are
D:been away from home, are
回答下列问题:
某22肽被水解成1个4肽,2个3肽,2个6肽,则这些短肽的氨基总数的最小值及肽键总数依次是 ( )
我国东部濒临的海洋自北向南依次是( )
观察图1和图2,请回答下列问题:
(1)请简述由图1变成图2的形成过程:____ .
(2)若AD=3,DB=4,则△ADE和△BDF面积的和为____ .