It can’t be Lucy’s bike. Look! ______ is under the tree.
----Shall we go to the amusement park this Sunday, mum?---- Sure, ________ I am busy.
This is the third time the famous scientist __________ the United States.
----Philip has gone to New Zealand.----Oh,can you tell me________?
No one can achieve success __________ effort.
----Drugs have done great harm to some people and their families.----Quite true, so we should ________ them.