Daniel didn't go to school.I didn't go, ______.[ ]
A. too
B. either
C. also
D. both
答案:B
若|a|=4,|b|=3,且|a+b|=a+b,则b-a的值为( )
A.-1
B.7
C.-1或-7
D.1或7
番茄的大小和果实的颜色是一对相对性状.______.