某市政府为了增强城镇居民抵御大病风险的能力，积极完善城镇居民医疗保险制度，纳入医疗保险的居民的大病住院医疗费用的报销比例标准如下表：
设享受医保的某居民一年的大病住院医疗费用为x元，按上述标准报销的金额为y元.
(1)直接写出x≤50000时，y关于x的函数关系式，并注明自变量x的取值范围;
(2)若某居民大病住院医疗费用按标准报销了20000元，问他住院医疗费用是多少元?
Manypatientsinsistonhavingwatcheswiththeminhospital,______theyhavenoschedulestokeep.
重写句子：Attheinternationalmuseum,youcanfindancientEgyptianart.YoucanexploreAfricanartifactsthere.Youcandiscoverbeautifultextilesfromaroundtheworldthere.(parallelstructure)
Theyshouldtryto________theirusualinhibitionsandjoininthefun.
流行性乙型脑炎的传染源是
句子写作：Suchanattitudewouldemphasizethevalueoflife.
