A:多肽
B:淀粉
C:纤维素
D:脂肪
请回答有关农业生态系统的问题:
○×(△+☆)=○×____+____×____
102×a=____×a+____×a
53+42=____+____
124+35+76 =(____+____)+35
35×43×4 =(____×____)×____
____×34+____×6=28×(____+____)
(18+26)×5 =18×____+26×____
103+28+97+72=(____+____)+(____+____)