题目

＿＿＿with the present global difficult economic situation, many people don’t dare to invest money in stock market any more.        A．To face  B．Having faced   C．Faced     D．Facing 答案：C 解析: be faced with表示“（被迫）面临着”，这里Faced with短语作原因状语。在下列固体中分别加入NaOH浓溶液，固体溶解但无气体生成的是 A．SiO2              B．Na               C．Al               D．NH4Cl