题目

Life is difficult.  It is a great truth because once we truly understand and accept it, then life is no longer difficult. Most do not fully see this truth. Instead they complain about their problems and difficulties as if life should be easy. It seems to them that difficulties represent(代表) a special kind of suffering especially forced upon them or else upon their families, their class, or even their nation. What makes life difficult is that the process of facing and solving problems is a painful one. Problems, depending on their nature, cause in us sadness or loneliness or regret or ange3. 为研究阳光对花生发芽的影响，李明同学设计了一组对照实验，在甲和乙两个花盆中种了花生，并对阳光、温度和水加以控制。下表中①、②两处应是(   )A.20°C、过多       B. 20°C、适量C.30°C、过多       D.30°C、适量