题目

阅读理解 Australian scientists are trying to give kangaroo-style stomachs to cattle and sheep in order to cut the greenhouse gases they send out, which is thought to be responsible for global warming. Thanks to special bacteria in their stomachs, kangaroo flatulence (肠胃气胀) contains no methane and scientists want to transfer that bacteria to cattle and sheep who produce large quantities of the harmful gas. While the usual image of greenhouse gas pollution is a billowing smokestack, pushing out carbon dioxide, farm animals' passing wind contribute a surprisingly high percentage of to在“探究浮力大小跟哪些因素有关”的实验时，根据下面已知的事实，你能提出什么猜想？（1）轮船从江河航行到大海，吃水线深度变化了。由此猜想：浮力的大小可能跟_______有关。（2）从井中提水，盛满水的水桶露出水面部分越多，提桶的力就越大。 由此猜想：浮力的大小可能跟 ________有关。（3）按下图中甲和乙完成实验，这两个实验验证了哪些假设？                                       ①甲验证：_____________________________________________________②乙验证：_____________________________________________________