Có bao nhiêu khẳng định đúng 

$$\begin{gathered} {\left(2-\sqrt{3}\right)}^x>0\forall x\in \mathrm{ℝ} \\ {\left(2-\sqrt{3}\right)}^x\ge 1\forall x\ge 0 \\ {\left(2-\sqrt{3}\right)}^x>2-\sqrt{3}\forall x<1 \\ {\left(2-\sqrt{3}\right)}^x<4 \iff x>2 \\ {\left(2-\sqrt{3}\right)}^x>2+\sqrt{3}\iff x<-1 \end{gathered}$$