题目

解方程1.8x−5.9=3.1 x+x=7 5∶x=∶ 答案：【答案】x=5；x=9；x=2【解析】略Considering his health, I advise him to ______ an hour or two each day to work out.A. set about?? ????????????? ????????????? B. set off?? ????????????? ????????????? ????????????? C. set up?? ????????????? ????????????? ????????????? D. set aside