Please do me a favor — ______ my friend Mr. Smith to Youth Theater at 7:30 tonight.
The famous reporter, who is said to have gone back to America last year, _____in China for almost twenty years.
The time and effort he has devoted during the past few years____ trees in that remote area is now considered to be of great value.
After five hours’ drive, they reached ____ they thought was the place they had been dreaming of.
— People should spare no efforts to protect the environment. — ________. Air pollution does harm to our health.
The _______ of students in our class are from the country; only five are from cities.