Many years ago, when we first went to Canada, we were driving through Montana to Colorado with our two children, then aged 8 and 11. As it was getting1we started looking for a hotel, only to find out that it was 2time in that part of the country, and all the hotels were3.

    Finally, around 9 o'clock in the evening, we 4at a gas station to fill up on gas. My husband asked for a 5 book and told the woman at the counter that we were trying to find a hotel. She told us it would be6 He tried for 15 more minutes. When he was 7 the woman, Linda, said she and her family8 nearby and would be happy if we spent the night at her home.

    My husband was 9 at her offer of generosity (慷慨). She called her son to10us, since she had to 11at the gas station till midnight.

When we reached their home, her husband 12 us. He invited us to have coffee and chat while we 13his wife. She came past 12 am. We asked if we could slip away in the morning so as not to14them. They said we were now 15 and we would have to have breakfast with them.

    Next morning, we ate breakfast, and when we were 16my husband asked if he could offer some 17.They would not hear of it and 18 we were their guests. We kept in touch for many years, and invited them to our 19 too. Over the years, we lost touch, but have 20 forgotten their kindness.

以下诗句或谚语与所蕴含的科学知识不正确的是（    ）

已知f（x）= $\{\begin{array}{c}ln\left(1-x\right)，x<0\\ x^2-ax，x\ge 0\end{array}$ ，且g（x）=f（x）+ $\frac{x}{2}$ 有三个零点，则实数a的取值范围为____．