题目

I had to visit my sister in another town because her husband   61  (be) very ill. My children stayed back in   62  (they) father’s care, except for the youngest. I was nervous taking a train journey alone with my one-year-old daughter. However, I gathered all my courage and boarded the train. It was   63  (surprise) that there were only three other passengers in that carriage, two old ladies and a young man. My daughter was crying, missing her dad. I tried to comfort her,   64  her crying wouldn’t stop. Just then the young man offered   65   (take) my baby into his3年前，父亲的年龄是儿子年龄的4倍，3年后父亲的年龄是儿子年龄的3倍，求父子今年各是多少岁？设3年前儿子年龄为x岁，则可列出方程：________．