题目

下列叙述正确的是（    ）A．稳定性:  H2S>HCL                                 B．碱性: NaOH>M g(OH) 2C．氧化性:  S>O2                                                                          D．金属性: Na>K  答案：B解析:考查元素周期律的应用。非金属性越强，氢化物的稳定性越高，A不正确。同主族元素自上而下非金属性逐渐减弱，金属性逐渐增强，C、D不正确。所以答案是B。  －Did you visit Taipei International Flora Expo(台北花博会)? －Yes．It is the world of flowers．You can see many kinds of flowers in different _________－red, pink, purple, yellow, black… [　　] A．sizes B．names C．shapes D．colors