1.abitof有一点儿2.abigdinner一顿丰盛的正餐3.abottleof一瓶4.acanof一听，一罐5.acupof一茶杯6.afew一些；少数几个7.afewdaysago几天前8.aglassof一玻璃杯9.adropofwater一滴水10.afamilyofthreepeople一个三口之家11.agreatmany非常多的12.agreetodosth.同意做某事13.ahalf一半14.akindof一种；一类15.alarge[great]numberof许多16.alittle一点，少量（+不可n.)17.alittle+比较级18.alongtimeago很久以前19.amomentlater片刻...
