阅读下文，完成各题。

书黄筌画雀

       黄筌画飞鸟，颈足皆展。或曰：“飞鸟缩颈则展足，缩足则展颈，无两展者。”验之信然。乃知观物不审者，虽画师且不能，况其大者乎？君子是以务学而好问也。

做“验证力的平行四边形定则”的实验时，步骤如下：

①在水平放置的木板上固定一张白纸．

②把橡皮条的一端固定在木板的A点，另一端连接两根绳套．

③通过绳套用两个互成角度的弹簧测力计来拉橡皮条使橡皮条与细绳套的结点伸长到某一点O，并记录O点的位置．

④此时需记录下两个细绳套的____ 和两个弹簧测力计的读数F₁、F₂．

⑤改用一个弹簧测力计把橡皮条与细绳套的结点拉长到____ 后，再记录下____ 和弹簧测力计的读数F′．

⑥用铅笔和刻度尺从力的作用点O沿两绳套的方向画直线．选好标度，按F₁、F₂的大小做两个力的图示．用三角板做平行四边形，求得合力F．

⑦比较一下，力F′与用平行四边形定则求得的合力F的大小和方向是否相同．

史学界对北魏孝文帝改革看法不一。有人认为北魏孝文帝是盖世英雄，也有人认为他是千古罪人。出现这种分歧主要是针对北魏孝文帝改革措施中的

    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.