Flu virus can live on shared objects ( doorknobs, keyboards, counters, etc ).病毒可以在共用物品表面生存 ( 门把手 、 键盘 、 柜台等 ).Counters can, of course, be made highly directional by the use of external collimation.当然可以利用外部准直法来提高计数器的方向性.H...
这个农民在地里犁地犁到半路的时候, 犁出一些很大的石头,几乎弄坏了他的机器.Halfway across the field , the farmer ploughed out some very large stones which nearly broke his machine.农民在种庄稼前必须犁地.A farmer must plow the land before planting crops.每年这个时候,农民们开始犁地....