Eachstudentistogiveashort___(speak)totherestoftheclassattheendofthesemester.
每个人都是平等的，不管他是总统还是马路清洁工。翻译
Forthoseinvolved,thescandalhasbeenavery________(pain)experience
一质点沿x轴运动，任意t时刻质点的速度为v=6+4t2(SI)，则在t=3s时质点加速度a=()
Expertshavefoundthatnormalsleepcanbedividedintofive______stages
