“不冒烟的森林火灾”是指( )
A:森林雷灾
B:乱砍滥伐
C:森林虫灾
D:毁林开荒
下列划线字解释全对的一组是( )
①合并,得5x=5;②移项,得4x+x=3+2;③系数化为1,得x=1.
— Would you mind my singing here?
— . Look at the sign. It says "Be quiet".
已知等比数列{an}的前n项和为Sn,若S4、S2、S3成等差数列,且a2+a3+a4=﹣18,若Sn≥2016,则n的取值范围为____