Tomhasbeenavegetarian____principleforyears.
A、inB
【句意】 多年来，汤姆一直是一个按原则行事的素食者。
【难点】 on principle意为“根据行为准则;按照原则”;in principle 意为“原则上;基本上;大体上”。for和by不与principle搭配。
I hope you will spend as much time as you can ________ your English.
I_______thatthere_______aneveningpartyonSaturdayevening.
Tom, with his parents______ to America. They_____ back in two weeks.
____,sheledalifeofcompleteseclusion.
How I _____ I could live on the moon.
