【单选题】It's hard to keep the children ________ when they can't go outside and play. [ ]
【单选题】已知AgCl 的 pKsp =9.80。若 0.010mol⋅L−1 NaCl 溶液与 0.020mol⋅L−1 AgNO3 溶液等体积混合,则混合后溶液中[Ag+ ](单位:mol⋅L−1 )约为
【判断题】零星砌体、地沟、砖过梁按设计图示尺寸以体积计算。
【单选题】“油改电”指的是对( )的供电方式的改造
【单选题】Every one of us likes jokes, because they can ________ us. [ ]
【单选题】The audience were ________ by his _______ performance on the stage.