白处的最佳选项，使短文通顺、连贯。选项中有一项是多余的。
Guan Jiayi is good at English and Chinese, but her maths isn't good. 31 .
One day, the clothes at Guan's mom's store are on sale, so there are many people.
32 , so she asks her to help out at the clothes store. When a woman walks in, Guan walks to her. The woman says she wants to buy a sweater. After some time, she says, " 33 . What's the price of it?" Guan says, "It is 800 yuan, but it's on sale. 34 . Uh, you need to pay 400 yuan." "I see. This is my VIP card. I can get a 20% discount (折扣), right?" "Oh, yes," Guan says, "Then, you just need to pay 80 yuan."
35 , asking, "Are you sure?" Then, Mrs Guan, Guan's mom, comes and says to the woman, "I'm sorry. You need to pay 320 yuan, please." Then, she looks at her daughter and asks, "Now, do you think maths is not useful?"
A. I'll take this yellow one
B. She doesn't think it's useful
C. This coat looks beautiful on me
D. You can take it at half price
E. Her mom wants to teach her a lesson
F. The woman looks at Guan in surprise
31. 32. 33. 34. 35.

31.B 32.E 33.A 34.D 35.F

我们可以根据上下文逻辑和购物场景的常识逐一匹配选项：
1. 31空：前文提到关佳怡擅长英语和语文，但数学不好，后文结尾妈妈反问她是否还觉得数学没用，B选项“她认为数学没什么用”可以很好地前后呼应。
2. 32空：前文提到妈妈的服装店大促、到店的人很多，后文说妈妈叫她来店里帮忙，E选项“她的妈妈想给她一个教训”，符合后文通过算账让她明白数学很有用的情节逻辑。
3. 33空：前文说明女士想买一件毛衣，按照购物流程，挑好商品之后才会询问价格，A选项“我要买这件黄色的”符合该场景逻辑。
4. 34空：前文说明毛衣原价800元正在促销，后文提到只需要付400元，D选项“你可以半价买下它”，800的半价正好是400，前后数值对应吻合。
5. 35空：关佳怡错误算出打完VIP折扣后只需要付80元，和正确价格相差极大，F选项“这位女士惊讶地看着关佳怡”，符合后续她询问“你确定吗”的反应。
剩余选项C提到的外套和文中的毛衣设定不符，是多余项。