—Dad, science is too hard for me.

—Oh, dear, if you keep listening ________ in class and do enough exercises, you’ll find it easy.

A．carelessly

B．easily

C．carefully

D．quickly

国税人员、扣缴义务人和委托代征单位（人）向基层国税机关领取票证时，必须拆包发放的税收票证有（）

A.退税专用凭证

B.视同现金管理的票证

C.税收转帐专用完税证