The operation could prolong his life by two or three years.
這次手術可使他多活兩三年。
Only with a few people could she be her real self.
只有和幾個人在一起時，她才能表現出真實的自我。
I could come next week, or the week after.
我可能下周來，或者再下一周。
Could you put me through to the manager, please?
請幫我找經理接一下電話好嗎？
Could you just help me with this box, please?
請幫我搬一搬這箱子好嗎？