参考答案

正确答案：C
解析：commitment意为“承诺，保证”，符合题意，如：If you have agreed to give a number of lectures， help to pay your brother's school expenses and give your sister ＄100 a year for clothes，you have quite a lot of commitments．假如你已答应讲若干次课，又补助你弟弟的学费，再每年给你妹妹 100美元的置装费，那么你就给了相当多的承诺。pe