【判断题】生产者剩余是指生产者获得的收入中大于它要求所得到的最低回报部分
【单选题】下列哪项对提高母猪采食量几乎没有促进作用?
【单选题】Although he is very old, _________ he works very hard.
【单选题】He is very old, ___ he still works very hard.
【简答题】A.He is very old now. B.He is in good health. C.He lives in the city now. D.He prefers driving a car.
【单选题】—_______he is very old, he works very hard. — Wow, great. I should learn from him.
【单选题】Mr. Brown is 70 this year. Although he is very old, ____ he works very hard.