He could just make out three people through the mist.
透过薄雾他勉强能看出有三个人。
The operation could prolong his life by two or three years.
这次手术可使他多活两三年。
The treatment should be repeated every two to three hours.
这种治疗方法应该每隔两到三小时重复一次。
Do it now please ─ not in three hours' time.
请现在就干，而不是三个小时之后。
There's room for three people in back.
后排有可容三人的空位。