由京沪高铁上四位旅客的谈话中，判断下列选项中属于人口迁移的是（    ）

某大学对$1000$名学生的自主招生水平测试成绩进行统计，得到样本频率分布直方图(如图)，则这$1000$名学生在该次自主招生水平测试中成绩不低于$70$分的学生数是(     )

增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。

删除：把多余的词用（＼）划掉。

修改：在错的词下画一横线，并在该词下面写出修改后的词。

注意：1).每处错误及其修改均仅限一词。

2).只允许修改10处，多者（从第11处起）不计分。

    Last summer vacation I did some fruit-picking. It was an interesting but pretty hard work. I had to start at 7 am and pick eight hours. But it was such cheerful and full of funny. Some of we had guitars, so in the evenings we had barbecues and play a bit of music together. I only got about $80 a week, but at least they gave me all my meal, and the food was not that awfully. Basic accommodation was also supplying. However, I'm afraid I won't be going fruit-picking this summer, because I've got a temporary job in town what pays better.