Inthosedays,theoldwomansitatthegateforhours,waitingforhersontoreturnfromthefront.
—Shallwetakeataxitheresincetimeislimited?
—________.Itshouldbehardtogetoneduringtherushhour.
某城市有大型、中型与小型超市共1500个，它们的个数之比为1：5：9．为调查超市每日的零售额情况，需通过分层抽样抽取30个超市进行调查，那么抽取的小型超市个数为()