T:Mary, set your alarm clock for seven tomorrow morning.

M:Why

T:I'm going to take you to your school to register for classes.

M:That's right. I haven't done that yet.

T:You can choose classes that you like at the school office.

M:Really

T:Well, there are core courses and electives.

M:What do they mean

T:Core courses are ones that you must take. Elective courses are ones that you get to choose for yourself.

湯姆：瑪麗，把妳的鬧鐘設定在明天早上七點。

瑪麗：為什麼？

湯姆：我要送妳到學校註冊選課。

瑪麗：對喔。我還沒辦理註冊。

湯姆：妳可以在學校行政室選擇妳喜歡的課程。

瑪麗：真的嗎？

湯姆：嗯，有必修課和選修課。

瑪麗：它們是什麼意思呢？

湯姆：必修課是妳必須上的課程。選修課則是妳替妳自己所選的課程。