I recorded the professor’s speech on my cellphone _____ I could listen to it several times later.

A．in case

B．now that

C．even though

D．so that

木工师傅做家具时，来回拉动锯条锯木头．锯条温度将升高．该过程主要通过（　　）

A．热传递使锯条的内能增加

B．做功使锯条的内能增加

C．热传递使锯条的内能减少

D．做功使锯条的内能减少