题目

 The sick woman is       weak        look after herself. A. too; to                  B. so; that       C. very; to             D. so; to 答案：A15．已知全集U={1，2，3，4}，A={1，2}，则满足A⊆B的集合B个数是（　　）A．2B．3C．4D．5