Question

When _______a hand, one should say “Thank you” or “It’s very kind of you.”

A．offered

B．to offer

C．to be offered

D．offering

Answer 1

A

试题分析：考查状语从句的省略句：当主从句的主语一致的情况，可以省略从句的主语和be动词，when offered="when" one is offered。句意：当被提供帮助的时候，人们应该说“Thank you”或“It’s very kind of you.”选A。
点评：如果主句的主语和从句的主语一致，且状语从句的谓语动词中有 be 动词，从句的主语连同be 可一起省略，该类状语从句多为时间、地点、条件、方式或让步等，连词为when, while, though, if, unless, although, as if 等，后面通常接分词、不定式、形容词、名词等。