【单选题】听力原文: There have been many great inventions, things that changed the way we live. The first great invention was one that is still very important today—the wheel. For hundreds of years after that there...
【单选题】听力原文: There have been many great inventions, things that change the way we live. The first great invention was one that is still very important today—the wheel. This made it easier to carry heavy thin...
【简答题】A.A very popular food plant: B.A plant with limited uses. C.A food plant which has been thoroughly used. D.A plant used as a main food on the Pacific Islands.