以下是can的四種用法的潤色和改寫：1. 作為情態動詞，"can"表達的是可能性或允許，用于詢問能力或請求許可。例如："Can you swim?"（你會游泳嗎？）2. "can"與動詞結合時，構成了一個動詞短語，用來描述某個動作或狀態是可能的。比如："She can play the piano."（她會彈鋼琴。）3. 當"can"與感知動詞如see, hear等連用時，它通常不用于進行時態。例如："I can see the stars at night."（我晚上能看到星星。）4. "can't"或"cannot"是"can"的否定形式，它表示不可能性、拒絕或禁止。例如："You can't leave the classroom during a test."（考試期間你不能離開教室。）改寫后的例句：1. When will I be able to receive my test results?（我何時能夠收到我的測試結果？）2. The capability to reduce the problem to two primary concerns is within our reach.（將問題簡化為兩個主要問題的能力在我們掌握之中。）3. The surgery could potentially extend his lifespan by an additional two to three years.（手術可能將他的壽命延長兩到三年。）4. Many children find it challenging to perform optimally in oversized classes.（許多孩子在大班課堂上發現難以有效學習。）5. The outcomes can be categorized into three distinct groups.（結果可以被分為三個不同的類別。）