【题目】You have become fatter than before; I think you should lose weight.
→You have ; I think you'd better lose weight.

【答案】ut；on；weight
【解析】句意：你比以前更胖了，我认为你应该减肥。put on weight固定短语“增加体重”，这是一个现在完成时的句子，因此答案为put on weight。