山西省简称“晋”，山东省简称“鲁”。这些简称源于下列哪一制度（ ）
下列在生活中看到的几种现象中，哪一种不属于过敏反应（ ）
根据情境及首字母提示填入适当的单词，使短文句意完整、通顺。Pen pal wanted His name is Wang Lei. He is a____ C_____ boy. He wants a pen pal in____ F_______ . He thinks it’s a very____ i______ country and he wants to learn some French. He____ l_____ in Beijing, China with his parents now. He is 14 ____ y______ old and his____ b______ is in November. He can speak Chinese and a little English. What are his ____ l______ ? He likes watching sports games on TV and ____ p_____ computer games with his friends. His favorite subject is computer science. It’s____ f______ . He doesn’t like math, because it’s too difficult. Please write to____ h____ and be his pen pal.
“蹦极”运动中，长弹性绳的一端固定，另一端绑在人身上，人从几十米高处跳下．将蹦极过程简化为人沿竖直方向的运动．从绳恰好伸直，到人第一次下降至最低点的过程中，下列分析正确的是（ ）
根据反应“A+B→C+D”，回答下列问题：
（1）若该反应为置换反应，B为稀酸，D为H2，则A应满足的条件是____ ．
（2）若该反应不属于基本反应类型，则可能的反应有 ____ ；____ ；____ ．
