一头大象的体重等于8头牛的体重.一头牛重506千克,一头大象的体重大约是多少吨?
506×8≈4000(千克);
4000千克=4吨;
答:一头大象的体重大约是4吨.
— Do you want anything else for your birthday?
— Nothing else. I'm very ____ with what you've bought me. [ ]
A. satisfying
B. disappointed
C. content
D. honest
电泳法和超速离心法能将血浆脂蛋白分为哪几类?简述各种血浆脂蛋白产生的部位和功能。