如图是某几何体的三视图，该几何体是（　　）

阅读短文，判断正误。

    Mr. Black has a bigfarm. There is a vegetable garden on the farm. You can see carrots, green beans, potatoes and tomatoes. On his farm, there are many animals, too. There are ducks, sheep, hens, horses and goats. Mr. Black likes his animals. He feels(感觉) happy. My friends and I often go to the farm and play with the animals. Some friends like horses and some like goats. I like sheep. We often help Mr. Black clean the farm.

中国农业从远古洪荒走来，经历了“刀耕火种”、“牛耕铁型”等阶段。下列项中属于“刀耕火种”阶段的耕作工具有（    ）

①石斧

②耧车

③骨镰

④曲柄锄

要在光屏上得到和物体一样大小的像，下列元件中应选用（  ）