题目

把一个西瓜皮轻轻放在水面上，能漂在水面上，而把它没入水中它却沉入水底，同学们通过对这一现象的分析，发现并提出一个科学问题。同学们提出的下面四个问题中，通过探究最能揭示这一现象物理本质的是A. 物体在什么情况下会受浮力？B. 物体所受浮力大小与哪些因素有关？C. 物体所受浮力产生的原因是什么？D. 物体的浮沉与浮力、重力有什么关系？听短文，回答短文后面的问题。(短文读两遍) 1. When do tigers live as a family? [     ]A. When they have wives B. When they have babies C. When they have sisters or brothers 2. Who teaches baby tigers to catch other animals? [     ]A. mothers B. fathers C. teachers 3. How do wolves hunt? [     ]A. hunt alone B. hunt together C. hunt with other animals 4. What do tigers usually eat? [     ]A. small animals B. big animals C. other animals 5. How do people feel when they see the wolves? [     ]A. happy B. exciting C. frightened