阅读资料，回答问题：

蚯蚓可作为动物的饲料．蚯蚓的体内含有人和动物体内所必需的多种氨基酸，其中含量最高的是亮氨酸，其次是精氨酸和赖氨酸等．将蚯蚓用于畜牧业和渔业中，据初步报道，每只猪每天喂给100～200g的蚯蚓，每天可增重0.25～0.5kg；而不喂蚯蚓的生猪，每天增重仅0.15～0.35kg．如用它喂养鲫鱼，成活率达99%～100%，增长率达38%～59%．蚯蚓可作为中药，它能治疗哮喘病；有清热解毒的功用；它的水浸出液具有麻痹知觉的作用；蚯蚓的酒精提取物有降压作用；此外蚯蚓还有镇痉、利尿和治外伤炎症等功效．蚯蚓是改良土壤的能手．蚯蚓能加速土壤团粒结构的形成，加强土壤中的水肥，增强土壤保水保肥的能力，加强土壤内的气体的通透性；促进气体交换，有利于土壤中微生物的繁殖和作物根系的生长，提高农作物的产量．蚯蚓在环境保护方面也有突出的表现．蚯蚓可用来处理造纸厂的污泥，以及酒厂和畜禽水产品加工厂的废物和废水；还能利用蚯蚓来处理城市垃圾．

为了鉴别一工艺品是否铜做的，小红和小海等几位同学做了以下实验：

⑴What did you do last Sunday? ____   A. Yes, I did.

⑵Where did Mike go?____           B. Because I wanted to give him a fish

⑶Did you watch a film yesterday?____  C. I visited my aunt.

⑷Where were you last night?____     D. There are six.

⑸Why did you call him?  ____         E. He went to the park.

⑹Let's go to the Summer Palace.____   F. No, there wasn't.

⑺How was the film?____             G. It was fun.

⑻Who brought the model ship?____    H. Good idea.

⑼How many bottles are there?____     I. I was in Nancy's house.

⑽Was there a park near here?____    J. Ben's father.

在△ABC中，AB=5，AC=3，BC=7，则∠BAC=（　　）