题目

 Will you please invite him _________ in a writing competition?            A. joins        B. to joining       C. to join      D. joining 答案：C如图，平行四边形ABCD中，P点是形内一点，且△PAB的面积等于8cm2，△PAD的面积等于7cm2，△PCB的面积等于12cm2，则△PCD的面积是 cm2．