_____ she is the only daughter of the boss, she started from the lowest position as a common employee.
A:Unless
B:While
C:Since
D:As
下列生活事例中,主要过程为化学变化的是( )
已知△ABC与△A1B1C1的相似比为2:3,△A1B1C1与△A2B2C2的相似比为3:5,那么△ABC与△A2B2C2的相似比为____