定量供应很久以前就结束了饼干过剩的状况。Rationing had put an end to a surfeit of biscuits long ago.我们都得排队领取定量配给票证薄。We all had to queue up for our ration books.很多基本商品现在都要定量供给。能买到的东西越来越少。Many basic goods are now rationed. Less and less is ava...
“那是一种粉虱，对吗？”——“是的，是粉虱。”"That's a type of whitefly, is it?"— 'Yes. it is a whitefly.'北京地区粉虱分类研究 ( 同翅目: 粉虱科 )A TAXONOMIC STUDY ON WHITEFLIES IN BEIJING ( HOMOPTERA: ALEYRODIDAE )结果表明,烟粉虱对供试植物有明显的选择性,其嗜好程度为花椰...