第22题: [单项选择]She stayed at home during the whole summer vacation ______ she could look after her old grandmother. A. in case B. now that C. so that D. as though 参考答案:C 答案解析:[解析] 本题考查的是从属连同so that的用法。C项中的so that可以引导目的状语从句,意为“以便”,本题中的主句是“She stayed at home”,从句“... she could