A:puzzled; puzzling; puzzling
B:puzzled; puzzling; puzzled
C:puzzling; puzzling; puzzled
D:puzzling; puzzled; puzzling
以下动物的行为,属于学习行为的是( )
已知线性方程组的增广矩阵为1161a2,若该线性方程组解为42,则实数a=____ .
When did the boy go to the zoo?
读图回答问题.