题目

 It was _____ the boss declared that the company would raise the workers’ pay _____ the reporters became excited.    A. when; that               B. as; which      C. since; for which    D. after; which 答案： A。本题为强调句型，对句中的状语从句（when引导）进行强调。pH = 2的A、B两种酸溶液各1mL, 分别加水稀释到1000mL, 其溶液的pH与溶液体积(V)的关系如右图所示, 则下列说法正确的是（    ）                    A．A、B两种酸溶液物质的量浓度一定相等 B．稀释后A酸溶液的酸性比B酸溶液强 C．若a = 5时, A是强酸, B是弱酸 D．若A、B都是弱酸, 则5 > a >2