Since we have a focused subject ，we should not talk ________.
A、atonceD
译文：既然我们已经有了命题，我们就不应漫无边际地交谈。此题考查对固定短语的掌握情况。atonce立刻;athand在附近，在手头，即将发生;atintervals间或，不时;atrandom随便，任意。
This is the most beautiful village _______ I visited these years.
Basically，theseattitudesamounttoabelief________leisurecanandshouldbeputtogooduse
Robots differ from automatic machines ________ after completion of one specific task，they can be reprogrammed by a computer to do another one.
Itisvitalthatthework_______intime.
Thegovernmentfinally________allthedocumentsrelatingtothewar.
