Are they studying biology?
请注意，上面的例句没有使用冠词。冠词通常不放在表示课程和语言的名词前。 然而，如果一门课程有of 介词修饰，要在该课程前加冠词。
how to...
We are learning how to speak Spanish.
About () 是介词，经常和speak, talk, tell 和learn 连用。