【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
【单选题】“油改电”指的是对( )的供电方式的改造
【判断题】在结构上,植物细胞一般具有纤维素或其他物质构成的坚硬的细胞壁。( )
【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.