________ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
Though I’ve tried very hard to improve my English, by no means ___________with my progress.
Science and technology have in important ways __________ the improvement of agricultural production.
Mr. Han, my neighbor, is always helping those who are in trouble without expecting anything __________.
He is very sick. I insist that a doctor __________ immediately.
In the novel, the two cities referred to __________ London and Paris.