“高钙奶”中“钙”是指（　　）

阅读短文，选择正确的答案。

      There is a park near our school. Wecan see many trees and flowers there. Some flowers are red, and some areyellow. We can see a hill behind the park too. At the foot of the hill we cansee a river. There are some boats on it. Children like to go there. It is springnow. There are many children in the park. Some are walking and singing. Some aredancing and playing games. Ann and her sister Kate are flying a kite. Tom andhis brother Sam are throwing a frisbee(飞盘).Their father and mother are sitting under the tree. They are all happy.

阅读材料，完成下列要求。

材料：有历史学者为说明近代以来科学技术在生产力发展中的作用，引用了如下公式：生产力=科学技术×（劳动力+劳动工具+劳动对象+生产管理）

这一公式表明，科学技术有乘法效应，它能放大生产力诸要素。

——摘编自齐世荣总主编《世界史》

运用世界近现代史的史实，对上述公式进行探讨

（说明：可以就科学技术与公式中一个或多个要素之间的关系进行论证；也可以对公式进行修改、补充、否定或提出新公式，并加以论述，要求观点明确、史论结合、史实准确。）

作为新时代的青少年，我们既要培养自己的权利意识，同时又要增强自己的义务观念。某校八年级（2）班同学组织了一次“权利义务伴我行”的宣传活动，请你也参与其中。