gồm có bốn cấp:

-Rất nguy cấp(CR):

vd:Ốc xà cừ,Hươu xạ,..

-Nguy cấp (EN):

vd:Tôm hùm đá,Rùa núi vàng,..

-Sẽ nguy cấp(YU):

vd:Cà cuống,Cá ngưa gai,..

-ít nguy cấp (nuôi được) [LR]:

vd:Sóc đỏ,Gà lôi trắng,..

\(\Rightarrow x=\dfrac{-1}{3}+\dfrac{1}{9}\\ \Rightarrow x=\dfrac{-3}{9}+\dfrac{1}{9}\\ \Rightarrow x=\dfrac{-2}{9}\)

C

\(2.\\ a.\dfrac{4}{3}-\dfrac{2}{5}=\dfrac{20}{15}-\dfrac{6}{15}=\dfrac{14}{15}\\ b.\dfrac{8}{7}-\dfrac{8}{9}=\dfrac{72}{63}-\dfrac{56}{63}=\dfrac{16}{63}\)

3.cửa hàng còn số gạo là:

\(\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{3}{5}\right)=\dfrac{3}{5}\)(tấn)

\(=\dfrac{\left(-3\right)+\left(-5\right)}{16}=\dfrac{-8}{16}=\dfrac{-1}{2}\)

1.How many languages are spoken by Canadian?
2.Where were the lost girl and the police last night?
3.đề sai !?
4.The letter was sent to paris last Sunday.