The earth moves round the sun, and the moon goes round the earth. When our part（部分）of the earth turns to the sun, it is day, When our part of the earth turns away from the sun, it is night. The sun is much bigger than the moon. But sometimes the moon looks bigger than the sun, because it's much nearer to the earth. The sun is very bright. It gives a very strong light. The moon looks quite bright, too. But it doesn't give any light at all. The moon looks much bigger and brighter than the stars. But actually（事实上）, the stars are much bigger and brighter than the moon. They look smaller than the moon because they're much farther away from us.

《九章算术》是我国东汉年间编订的一部数学经典著作，在它的“方程”一章里一次方程组是由算筹布置而成的．《九章算术》中的算筹图是竖排的，为看图方便，把它改为横排，如图（1）、（2），图中各行从左到右列出的算筹数分别表示未知数x，y的系数与对应的常数项，把图（1）所示的算筹图中方程组形式表述出来，就是$\left\{\begin{array}{c}3x+2y=19\\ x+4y=23\end{array}\right.$类似地，图（2）所示的算筹图可表述为（　　）

             图1                                           图2