单选题 Peter, (together with) his wife and (two sons), (are) to arrive (on the) evening flight.
【正确答案】 C
【答案解析】应为is。Peter是该句主语，根据主谓一致的原则，谓语应用单数，在类似的句式中，不要被插入成分(together with his wife and two sons)所迷惑。