根据万国邮联对速递不平衡补偿费的规定，只要当不平衡差额超过（）时，才需要结算不平衡补偿费。
A.50
B.80
C.90
D.100
参考答案：D
— Alison, I'm sorry. I can't come to the wedding with you tomorrow morning.
— ______?
— My grandma was severely ill, so I have to stay in the hospital to look after her. [ ]
A. How is it
B. How come
C. So what
D. What's the problem
国家鼓励和支持农业生产者和相关企业采用先进或者适用技术，对下列哪些物质进行综合利用？
A.农作物秸秆
B.畜禽粪便
C.农产品加工业副产品
D.废农用薄膜
