如图，是一个长为30 $m$ ，宽为20 $m$ 的长方形花园，现要在花园中修建等宽的小道，剩余的地方种植花草．如图所示，要使种植花草的面积为532 $m^2$ ，那么小道进出口的宽度应为____  $m$ ．

根据汉意选择合适的单词填空。

north      south

当黑龙江省冰天雪地时，海南岛依然百花盛开，这是因为我国（ ）

用如图所示的实验装置测量杠杆的机械效率．实验时，竖直向上匀速拉动弹簧测力计，使挂在较长杠杆下面钩码缓缓上升．实验中，将杠杆拉至图中虚线位置测力计的示数F=____ N，钩码总重G为1.0N，钩码上升高度h为0.1m，测力计移动距离s为0.3m，则杠杆的机械效率为____ 　%．请写出使用该杠杆做额外功的一个原因：____ ．

C

    Next week is Family Learning Week and there will be many activities (活动) at schools in the city.

    There is a very interesting art class at Hadley School. Its name is "Paint with your parents". It's on Saturday, October 28th. It is for anyone with children under 16. It's a two-hour class it begins at 9:15 in the morning

    An interesting thing about this class is one of the teachers, a famous writer. Her name is J.P. Hayward She will read from her new book. Listening to her will give you ideas to use in your paintings.

    A family ticket (票) is $8. That's for four people. Anyone extra (额外的) has to pay (付费) $3.

    If you are interested in this class, please call Mr. Henry. The phone number is 456-3290. I hope you all enjoy Family Learning Week.

根据材料内容选择最佳答案。