不当得利
参考答案：
是指没有合法根据而获得利益并使他人利益遭受损失的事实。
John Snow became inspired when he thought about helping ordinary people
Cholera.
A．led to
B．contributed to
C．exposed to
D．absorbed into
跳汰用风一般有（）两种
A、高压风
B、中压风
C、低压风
D、变压风
E、稳压风
F、变压风
