As we know, English is w____ used around the world. But can all English speakers understand each other all the time? Of c____ not. ____（甚至）the same word can have many different meanings. Sometimes the meaning can change, depending on the country where it is ____（说）. For example, there are differences between British English and American English. Also, Australian English is a little different from British English. If you want to succeed in making y____ understood, you need to know some of these differences.

如图所示，一质量为m的小球固定于轻质弹簧的一端，弹簧的另一端固定于O点处，将小球拉至A处，弹簧恰好无形变，由静止释放小球，它运动到O点正下方B点间的竖直高度差为h，速度为v，则（   ）

阅读材料及非洲示意图，完成下列问题

材料：2014年2月．com/doc/5882424．html“/t“_blank“西非爆发埃博拉疫情，此后，埃博拉疫情在几内亚、利比里亚、塞拉利昂、尼日利亚等西非国家蔓延．疫情爆发后，中国政府已先后提供了4轮总价值7.5亿元人民币的紧急援助．中国援非医疗队克服高温天气和被感染的危险，在协助西非国家对抗埃博拉疫情发挥积极作用．

世界上绝大多数动植物都能在我国找到适合生长的地区，主要是因为我国（   ）