单项选择题
A.to sing B.sang C.sing D.sings
In some parks visitors are requested to keep（）the grass...
单项选择题In some parks visitors are requested to keep（）the grass.
A.aside B.away C.out D.off
In order to（）your goals, you must work hard.A.makeB.ach...
单项选择题In order to（）your goals, you must work hard.
A.make B.achieve C.require D.develop
In order to（）the disease, the first thing we should do ...
单项选择题In order to（）the disease, the first thing we should do is to do research about it and find out a satisfactory cure.
A.confirm B.conduct C.control D.confuse
