________(occupy) with his work in the Satellite Launch Site, he could not spare any time to stay with his parents though they are very old.
The manager asked me to______ the report, because he didn't want to speak for a long time at the meeting.
With the word "PM2.5"______ heard and seen in our life, people become more and more concerned about air pollution.
— The deadline is drawing, but I failed to challenge the task a third time.— ______ my brother have a try?
Mr. Zhang once taught in a remote village in Anhui province as a volunteer, which was ______ only on foot.
Wherever he is, he makes ______ a rule to give his mother a call every day.