It’s very funny that many people who lose weight gain it back after some time and end up back __________ they started.
A．when B．after C．since D．where
The U. S．declares it has the best medical technology in the world，but quite a lot of Americans have no __________to health care service．
A．devotion B．entrance C．access D．introduction
The DiaoYu Island have been part of China’s territory since ancient times, __________as important fishing grounds of Taiwan.
A．served B．serving C．to serve D．having served
Sun Yang, a young Chinese swimming talent, ___________several gold medals before 2012 London Olympics.
A．won B．has won C．had won D．were to win
The government has taken some measures to solve the shortage of electricity, but it may be some time ____________ the situation improves.
A．since B．when C．unless D．before
Mary had to go to a meeting，so she left her children ___________ at home.
A．playing B．played C．to play D．having played
