种植春天

    从前，有一位国王，性格冷酷。他的国度里所有的地方都盖在厚厚的白雪之下，从来就没有花的芳香和草的翠绿。他十分渴望春天来到他的国家，但是春天从来都不肯光临。

    这时，一位流浪已久的少女，来到了王宫的门前。她恳求国王给她一点食物和一个睡觉的地方，她实在太饿太累了，但是国王从来都不愿意帮助别人，他叫随从把少女赶走了。

    可怜的少女在肆虐的风雪中走进了森林。在森林里，她遇到一位厚道的农夫。农夫急忙把她扶进屋，让她睡在温暖的火炉边，给她盖上毛毯，然后用仅有的面粉为少女做成了面包和热汤。当他把面包和汤端到少女面前时，才发现少女已经死了。

    农夫把少女埋在了田野里，并把面包和汤放进去，还为她盖上了毛毯。。第二天一早，奇迹出现了：尽管其他地方仍旧白雪皑皑，但是少女的坟墓上，竟然开满了五彩斑斓的小花——这里的春天来了！

    原来，这个少女便是春天。

下列词语中划线字读音全都正确的一组是 (　　)

    Most American families are smaller than the families in other countries. Children in the USA will leave their parents when they grow up. They usually live far from their parents because they want to find good jobs. They often write to their parents or telephone them. And they often go to visit their parents on holidays.

    Parents usually let their children choose their own jobs. Americans think it is important(重要的) for them to make decisions(作决定).

    Children are also asked to do some housework at home. And in many families，children will get money from their parents for doing some housework. Because American parents want to let their children learn how to make money for their own use.

2-丁烯是石油裂解的产物之一，回答下列问题：