数一数．

有____条线段

    Strange things happened in Tangshan. ____ three days, water in the wells kept ____ (rise) and falling. ____ (smell) gas came out from the cracks of wells. Animals became ____ (nerve). There were other signs of an earthquake but the people thought little of these events. At 3: 42 a. m., everything began to shake. The world seemed ____ (be) at an end. One-third of the nation felt the ____ (great) earthquake. In fifteen seconds the city lay ruins. Two-thirds of the people died or ____ (injure). Thousands of families were killed and many children were left ____ parents. Then later that afternoon, ____ big quake shook Tangshan. People began to wonder how long the disaster would last. ____ all hope was not lost. Soldiers came to help the rescue work. Slowly, the city began to breathe again.

有关下列几种动物的叙述，错误的是（    ）

如果对于函数f（x）定义域内任意的两个自变量的值x₁，x₂，当x₁＜x₂时，都有f（x₁）≤f（x₂），且存在两个不相等的自变量值y₁，y₂，使得f（y₁）=f（y₂），就称f（x）为定义域上的不严格的增函数．

则 ①$f\left(x\right)=\left\{\begin{array}{c}x,x\ge 1\\ 0,-1<x<1\\ x,x\le -1\end{array}\right.$，②$f\left(x\right)=\left\{\begin{array}{c}1,x=-\frac{\mathrm{\pi }}{2}\\ \sin x,-\frac{\mathrm{\pi }}{2}<x<\frac{\mathrm{\pi }}{2}\end{array}\right.$，

③$f\left(x\right)=\left\{\begin{array}{c}1,x\ge 1\\ 0,-1<x<1\\ -1,x\le -1\end{array}\right.$，④$f\left(x\right)=\left\{\begin{array}{c}x,x\ge 1\\ x+1,x<1\end{array}\right.$，

四个函数中为不严格增函数的是____ ，若已知函数g（x）的定义域、值域分别为A、B，A={1，2，3}，B⊆A，且g（x）为定义域A上的不严格的增函数，那么这样的g（x）有____ 个．