– Mum, would you please buy me a MP5 player?
– If you can help do the dishes the whole vacation，you have one as a reward·
A. must
B. need
C. would
D. shall
网友回答
A. must
B. need
C. would
(答案→)D. shall
解析：考查情态动词。must 必须，need 需要，would 将会，shall 用于二三人称表示一种一种情绪，警告，允诺，规定等等，句意：妈妈，请你给我买一个MP5播放器吧?在整个假期如果你帮助洗碗筷的话，作为奖赏可以给你卖个。根据语境应用shall，在这里表示允诺，故选D。