单项选择题
A.It has many big and beautiful parks. B.It possesses many historical sites. C.It is a city of contrasts. D.It is an important industrial center.
A.It has a dense population. B.It has many towering buildings. C.There are 200 vehicles for every kilometer of roadway. D.There are many museums and palaces.
A.They could drive the insects away. B.They could keep the plants well watered. C.They could build devices to trap insects. D.They could make the plants grow faster.