下边加线字注音正确的一项是（　　 ）。

小伟在测液体的密度时，采用的步骤如下：A、用天平称出烧杯与少部分液体的质量m₁；B、用量筒量出一些液体的体积V并将量筒中的液体倒入烧杯中；C、用天平称出烧杯与液体总质量m₂；D、根据密度公式：ρ=$\frac{m_2-m_1}{v}$；小伟用这样的步骤测出的密度与真实值相比 ____（选填“偏大”或“偏小”），如果将B步骤改为从烧杯中倒出适当的液体到量筒并读出液体体积v，那么正确的步骤应该是　 ____　，小伟按正确的步骤实验后，得到如图所示的结果，液体的密度是　 ____kg/m³．

阅读理解

    “Billy, one, two, three, get up! It is 25^th February, 2099, seven' o'clock．It's time to get up and go to school, ”says the clock-robot in a loud voice．Then the clothing—robot dresses(给……穿衣服)Billy quickly．Next the kitchen—robot gives Billy some bread and eggs.  Billy doesn't like them, and the kitchen—robot gives him a hamburger．After eating the hamburger, Billy goes to school．When he gets out of the house with his schoolbag, he sees a car-robot waiting for him．“Hello! I will drive you to school．Your name is Billy, isn't it?” asks the car．“Right．”Billy answers．“Now would you please show me your school ID card?” says the car．Billy shows it his school ID card．“Get in, please．”Billy gets in it．Then the car goes on, “l will check your homework today．Please take it out．”Billy does as what the ear-robot says．When they get to school, the car says to Billy, “See you tomorrow, Billy．Good luck!”

He _______ computer games when his parents left home. So he didn't know where they were.