A．by contrastB．in practiceC．in particularD．on average

A．in return B．in turnC．by hand D．in silence

【C3】A．in returnB．in turnC．by handD．in silence

【C9】A．in a wordB．by the wayC．in other wordsD．in addition

【C10】A．by contrastB．for instanceC．in additionD．however

【C18】A．By contrastB．In a wordC．In generalD．By the way

In the opening paragraph, the author introduces his topic by______.A．posing a contrastB．ju