【单选题】Barry had an advantage over his mother ______ he could speak English.
【单选题】( )用于办理证券金融公司与转融通业务有关的资金结算。
【简答题】输出信号的频率比输入信号的频率高n倍的电路叫( )。
【单选题】由A、B点的高程HA=100米,HB=200米,求高差hAB=( )米
【单选题】If you want to speak English well, it’s ___ for you to practice as often as you can.