The teacher came in ____ a book under his arm. [ ]

He often gives me some advice.The sentence structure is________.

Taobo is Asia’s largest retail（零售的） network platform, ______ people can buy and sell many kinds of things．

He gave me two answers_________the question,but________of them is right.

Are you pleased with her work, sir?— Not at all, It couldn’t be any _____.