______ twice a year,whether it is a car or a truck,is the rule that every driver must obey in this city.
Only when he met the girl his aunt introduced to him ____ that he had seen her before.
— Shall we go for a walk ________ watch TV? — That’s a good idea.
You can’t have lost the keys.___ all your pockets again.
-We need an immediate reply. –I see . I’ll send the paper to you_____.
—Have you heard of the nuclear test in that country? --Yes, _____news came as ___shock to me.