题目

Houston Rockets center Yao Ming of China would not play for the rest of the NBA basketball season _____ his foot injury on Tuesday.     A. due to          B. as to              C. according to       D. in addition to   答案：A10．如图，在Rt△ABC中，∠ACB=90°，AB=4．分别以AC，BC为直径作半圆，面积分别记为S1，S2，则S1+S2的值等于（　　）A．2πB．3πC．4πD．8π