22. Please tell me how the accident_____. I am still in the dark.
.—Must I give the pen to the manager ? —No, you may give it to________you think is on duty in the office .
.Look! The dictionary, ________cover is red, is a birthday gift given by Tom.
_______environmental damage is done, it takes many years for the ecosystem to recover.
.Every possible means _______to prevent the air pollution, but the sky is still not clear.
.______ surprised the family most was ________the girl played basketball very well.