18.What do flash-players normally do?A.) They find companions through newspapers.B.) They assemble in a private house to have a party.C.) They set up fixed groups and meeting time.D.) They get together for only one day.

正确答案为D 你没有作答。解析：音频中提到，这些人花一天的时间在一起，分手之后就不会再见（spend the day with a stranger, part at the end ofthe day and never see each other again），所以选 D。ScriptCall it a product of the local foods movement. Butwhatever the reason, more Americans are growing someof their own food.Many need advice from experts like the mastergardeners at the University of Maryland Extensionservice. The extension service has launched a campaignas a response to the huge new demand for informationand help with home gardens. Master gardeners arehelping less experienced people learn how to work theland. Food gardeners can join a network and put theirgarden on a map on the extension service web site.They aim to have one million food gardeners in Marylandto produce their own affordable healthy food. Thecurrent count of food gardeners is around 5,000statewide.Nationally, sales of garden supplies increased last yearas people started or expanded food gardens. ShannonDill says the weak economy is not the only reasonpeople are trying to grow their own food to save money.Prices for fruits and vegetables at the store are up.Shannon Dill finds that growing food at home usuallycosts less than buying it at stores or restaurants. Shealso finds that people seem to be staying home more, sothey have more time to work in the garden. And, shesays, "People like to know where their food is comingfrom."But sometimes people choose the wrong plants for thelocal growing conditions. Or they plant at the wrongtime. Or they plant seeds too close together or in poorsoil or without enough daily sunlight. Master gardenerscan help people avoid mistakes.