读南、北美洲两种气候类型的分布图, 下列关于①、②气候特征的叙述,正确的是  (    )

    We had an awful school trip last week. Some students were late. Then we waited half an hour for the school bus, but it didn't arrive. Finally, our teacher took us to take the subway. It took over an hour. Then we walked a long way. When we arrived at the zoo, it was already 12:00. We were all tired and hungry. We wanted to see pandas, but there weren't any. There were some really smart dolphin（海豚）,but we didn't see the show because we arrived too late. We forgot our cameras, so we couldn't take any photos. Then it started to rain, and no one had an umbrella. We didn't see many animals because of the rain. So we went for lunch. We ate hamburgers. My friends also had some ice-cream. But I didn't have any, because I don't like it. I wanted French fries, but there weren't any in the shop. They were sold out! Finally we went back to school. We were wet, tired and stressed out. I didn't enjoy my school trip at all.

如图所示，电源电压不变，当开关S由断开到闭合时，电压表的示数 ____，电流表的示数 ____

植物必需的有机物是通过____ 合成的，光合作用实现了两个转化：一是将无机物转化为____ ，二是将光能转化为____ 。