【简答题】A.Customers don't like the traditional hamburgers any more. B.They want to attract more children. C.They want to make their food more nutritious. D.They hope to satisfy all kinds of customers.
【简答题】A.Because their environment is becoming more and more dirty. B.Because the traditional ways of treating wastes are not efficient. C.Because they are short of useful materials. D.Because they need new ...