which scientist discovered that objects in water are lifted up by a force that helps them float?可以帮我翻译一下吗?谢谢了~

which scientist proposes that Day Star could not detect which operating system is in this disc image.you will need to fabs(disc) compact disc compact disc checking disc adhere disc 摄像机disc MY DISC DISC是什么 什么是disc? DISC是什么 center disc u-disc which scientist proposes Day star哪个科学家发现了启明星快 The stories of the famous scientist,___this is one example,are well writen.which ,为什么不用 about which? the scientist “scientist”是什么意思?