(1) (2007 - Guangdong) A bus travels from location A to location B at a constant speed of $60 \mathrm{~km} / \mathrm{h}$ for 1 hour, 

stays in location B for half an hour, then travels to location C at a constant speed of $80 \mathrm{~km} / \mathrm{h}$ for 1 hour. Among the following graphs describing the relationship between the distance $s$ traveled by the bus from location A, through location B, to location C, and the time $t$, the correct one is ( ).
Solve $s=\left\{\begin{array}{cc}60 t, & 0 \leqslant t \leqslant 1, \\ 60, & 1<t \leqslant 1.5, \\ 80(t-1.5)+60, & 1.5<t \leqslant 2.5,\end{array}\right.$