每到春暖花开时,蜜蜂都要忙着采蜜。蜜蜂的一生所经历的阶段是( )
直线L1:ax+3y+1=0,L2:2x+(a+1)y+1=0,若L1∥L2,则a的值为( )
— Yes, every Saturday my family and I go there to see the movies.