1.根据式子“我们已经×45+25=是是是是是”可知,等号右边“是是是是是”代表的数的末位数字要么是0,要么是5,又由题意可知应为5.再观察、比较下面几个式子等号左边,可知从上到下运算结果依次增大,由此可以求解,如图1.因此,“我们已经是中学生了”表示的九位数是123456789. 1. According to the formula “we have × 45 + 25 = yes yes yes yes ”, the right side of the equal sign “is yes yes yes yes ” the last digits of the number represented either 0, or 5, Again by the captions we should know 5. Then observe the comparison of the following equations on the left of the equal sign, we can see from top to bottom operation results in turn increase, which can be solved, as shown in Figure 1. Therefore, “We are already high school students The ”means the nine digits is 123456789.