In March 2013, Xi Jinping, ____ leader of the Chinese Communist Party, was warmly received by Putin, who was elected ____ president of Russia two years ago.
Carbon dioxide, which makes a _____ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.
______ your brother or you to blame for the broken TV set?
A large quantity of information, as well as some timely help, ______ since the organization was built.
More than one high official ______ by the police since the mayor was shot dead.
John is the only one of the students in the class that never ______ a mistake even when it is pointed to him.