题目

 (The students are having a discussion about health issues. ) S1: In my opinion, a healthy life should include two aspects: physical health and mental health. So a person ____61____ lacks either is not a healthy person. I think of several issues that may concern people most, namely, food security, medical service problems, AIDS and effects of environmental ____62____ (pollute) on health. S2: I think that drug taking is particularly destructive. As we all know, drug taking ____63____(do) great harm to people's health; it will ____64____ (gradual) kill a person if he gets ____65____ (a(16分)恒温时，将2molA和2molB气体投入固定容积为2L密闭容器中发生反应：   2A(g) + B(g)  xC (g) + D(s)，10s时，测得A的物质的量为1.7mol，C的反应速率为0.0225mol·L—1·s—1；40s时反应恰好处于平衡状态，此时B的转化率为20%。（1）x =    　      （2）从反应开始到40s达平衡状态，A的平均反应速率为   　 （3）平衡时容器中B的体积分数为     　  （4）该温度下此反应的平衡常数表达式为   　   数值是     （5）下列各项能表示该反应达到平衡状态是           A．消耗A的物质的量与生成D的物质的量之比为2∶1　　B．容器中A、B的物质的量 n(A)∶n(B) ="2∶1" C．气体的平均相对分子质量不再变化　　　D．压强不再变化E．气体密度不再变化（6）在相同温度下，若起始时c（A）="5" mol·L-1，c（B）=6mol·L-1，反应进行一段时间后，测得A的浓度为3mol·L-1，则此时该反应是否达到平衡状态     （填“是”与“否”），此时v（正）   v（逆）（填“大于”“小于”或“等于”）。