A:been dead; was killed
B:died; was killed
C:been dead; killed
D:died; killed
如图所示用弹簧测力计拉着木块向右加速运动的过程中( )
关于等温线图的判读,不正确的是( )
若a5=b7=c8,且3a-2b+c=3,则2a+4b-3c的值是( )
80=____