We must listen to the teacher ________ possible.
A:as careful as
B:as carefully as
C:as more careful as
D:as more carefully as
在学校里,老师就是____。
已知如图在Rt△ABC中,∠C=90°.CD是斜边AB上的高,若得到CD2=BD•AD这个结论可证明( )
地球是人类共同的家园,地球上的自然资源是( )