When            to someone,I usually say, "Pleased to meet you."

introduce

introduced

introducing

am introduced

考查过去分词和省略。句意：当我被介绍给别人时，我通常会说：“很高兴认识你”。根据句子结构可知，本句是when引导的时间状语从句，原句when I am introduced to someone,这里当从句主语与主句主语一致时，并且从句的谓语动词有be这时从句的主语与be同时省略，所以空格处introduced。故选B项。

It’s his brother ______ never been to Australia. You’d better take him with you.

that is

who is

that have 　

 who has

句意：就是他的弟弟从没去过澳大利亚。你最好带他和你去。根据句意及题干分析此题是考查强调句型，因为强调的是his brother，是人，所以用who引导是现在完成时态，故选D。

We played well, but I felt the team were            by one member, who didn’t try his best on the court.

let down

turned down

picked up

cheered up

考查动词短语辨析。句意：我们打得很好，但我觉得有一个队员在场上没有尽最大努力，让整个球队失望了。A. let down 使失望，放下；B. turned down 拒绝，调小；C. picked up捡起，接；D. cheered up使兴奋，振奋。结合句意可知，“有一个队员在场上没有尽最大努力”，所以“我们”感到失望。故选A项。