简述预防接种的禁忌症。
参考答案：
已知（x+y）2=11，（x﹣y）2=39，求x2+y2与xy的值．
The speaker is giving rather an _____ speech, as I can judge from the _____ look of all the listeners. [ ]
A. inspiring; inspiring
B. inspired; inspired
C. inspiring; inspired
D. inspired; inspiring
