人工智能产生于哪一年（）。
A.1957
B.1962
C.1956
D.1979
参考答案：C
He's a new bike for three weeks. [ ]
A. buy
B. buying
C. had
D. bought
下列光线在空气与水的界面处发生反射和折射的光路图中正确的是
