【题目】The letter ________ Tommy received from his company yesterday is very important.
A.who
B.where
C.what
D.that

【答案】D
【解析】句意：昨天Tommy收到的公司的来信非常重要。句中包含定语从句，先行词是The letter，指物，在定语从句中作received的宾语，用关系代词that引导，故选D。