He lives _______, but he never feels _______, because he likes reading.
A:lonely; alone
B:alone; lonely
C:lonely; lonely
D:alone; alone
sin70∘sin20∘cos2155∘−sin2155∘的值为( )
已知a,b两数在数轴上的位置如图所示,则化简代数式|a+b|﹣|a﹣1|+|b+2|的结果是( )