我昨天在这儿买的笔芯不好写。我能更换吗？
B：Oh, I'm sorry for the trouble caused you. Yes, of course you may change them. You can choose for yourself which sort to take in exchange.
哦，很抱歉给您带来麻烦。当然，您可以更换的。要换哪一种，您自己挑吧。
cause /k??z/ v. 引起；使产生 n. 原因
choose /t?u?z/ v. 选择
借给某人笔芯 lend someone a refill
A：I ran out of refills. Could you lend me one?