皮皮学，免费搜题
登录
搜题
【单选题】
1维持蛋白质一级结构稳定的主要化学键是A.
肽键
B.
二硫键
C.
离子键
D.
氢键
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】听力原文：As you know, Wellington Corporation is a global company so we sell our products all over the world. Our best-selling international product is our headphones. We do sell a lot of calculators, ster...
A.
It has sales in 36 countries.
B.
It increased its sales by 18 percent.
C.
It recently opened an office in London.
D.
It sells products through its Website.
【简答题】听力原文：M: Our commercials are designed to sell our message, company, and product. We always try to appeal to their emotions in some way, because failing to do this might be the same as throwing money ou...
相关题目：