D. Vitamin C is unusual in that it is required in the diets of humans and other primates, but only ofa few other animals.but only ofa few other animals.是什么成分？
when falling at speeds up to 60 miles per hour, cats stretch their legs which increases their air resistance and reduces the shock ofimpact on hitting the ground.还有at speeds up to 中的up to 是：直到（达到）的意思吧
No longer. TheInternet-and pressure from funding agencies, who are
questioning why commercial publishers are making money from government-funded
research by restricting access to it- is making access to scientific results a
reality. The Organization for Economic Co-operation and Development (OECD) ...
You only hear about theanimals that survived the flood.But sometimes I wonder if there were some cool animals that didn't make it on to the boat.这句话中on to the boat里面on是作副词修饰介词短语to the boat,表示在船上吗？如果是这样为什么不直接用 on the boat,这两...