一个语法问题

ivyleague

什么时候定语从句中 that 或which可以省略？

例如：The modern automobile is a ____ composed of more than 14,000 parts.

A. complex technical system

C. comples technical system that

答案选A

ivyleague

謝謝xiaobushi...那這個句子The modern automobile is a ____ composed of more than 14,000 parts 是不是省略了 that is ??

ivyleague

thx!!!