保护大自然，保护人类生存的环境，其实就是在保护我们人类自己。 [ ]
√
____ to teaching, as we know, contributes to his popularity with his students.
A．To devote
B．Devoted
C．Being devoted
D．Devoting
执行下列程序的结果是
main( )
float x=1,y;
y=++x*++x;
cout＜＜y＜＜endl;
A．9.000000
B．6.000000
C．1.000000
D．程序有错误
