Things lost sometimes just turn up ________ you never expect to find them.
In many countries, packets of cigarettes come with a government health warning ______ them.
— I am sorry the traffic is so heavy. — Does that _______ why you are so late?
I didn’t see her in the meeting room this morning. She _______ at the meeting.
The boy decided to climb the mountains _______ he knew he would face many difficulties.
China has been pushing the reform of public hospitals _______ all its citizens.