满足tanx<0的x值范围是( )
A:x|-π2+kπ<x<kπ,k∈Z
B:x|-π2+2kπ<x<2kπ,k∈Z
C:x|kπ<x<π2+kπ,k∈Z
D:x|2kπ<x<π2+2kπ,k∈Z
材料一:西岳华山位于陕西西安以东约120km处。华山由一整块花岗岩构成,可谓独石成山,山体形态如刀削斧劈般绝壁陡立,素有“奇险天下第一山”之称。
材料二:渭河平原位于陕西省中部,号称“八百里秦川”,自古农业发达,人口殷实,成就了古都西安的辉煌,是中华文明的重要发祥地。
材料三:北宋科学家沈括曾沿着太行山北行一路考察,看到“山崖之间,往往衔螺蚌壳及石子如鸟卵者,横亘石壁如带”。他猛然顿悟,“此乃昔之海滨,今东距海已近千里”。进而,推断了整个华北平原的形成过程。
读图,回答下列各题。
根据下列装置,结合所学化学知识回答下列问题.
No. 1 Middle School
Don't run in the hallways
Don't bring food into the classroom.
Don't listen to music in class.
You have to wear a uniform.
No. 2 Middle School
Don't bring food into the classroom
Don't wear a hat in class.
Don't go into the classroom without the teacher.
No. 3 Middle School
Don't listen to music in the classroom.
Don't run in the hallways.
You have to wear sports shoes for gym class.