除非民航局另有授权,在什么情况,机长需要相应型别等级?
B
暂无解析
“It was very cold testerday. ”
“_____.”
正常足月新生儿开始喂母乳的时间是()
It ‘s_____my power to make final decision on the matter.
ORS溶液不宜用于()
________,he had no time to rest.