未知题型 A school bus has 10 double seats in each of 2 rows. Two students can sit in each double seat. If an empty bus starts out and makes two stops, picking up three times the number of students at the second stop as at the first stop, and if the bus is then filled to seating capacity, how many students got on the bus at the second stop?E.30

判断题 一个机械结构只能建立一个装配尺寸链

未知题型 If B is the midpoint of line segment AD and C is the midpoint of line segment BD, what is the value of AB/AC?E.1/4