這三個詞都有組成構成的意思，compose作為構成的意思的時候應該是用被動語態consist是不及物動詞，得加介詞用 consist of

constitute 是及物動詞，不需要加介詞of

這三個詞都有組成構成的意思，compose作為構成的意思的時候應該是用被動語態Be composed of,例如Water is composed of hydrogen and oxygen.

consist是不及物動詞，得加介詞用 consist of，例如The United Kingdom consists of Great Britain and Northern Ireland.

constitute 是及物動詞，不需要加介詞of，例如 Twelve months constitute one year.而且constitute一般多用於機構 ，組織的構成

本題應該選D

A選項的話，句子應該改成Nearly 25%of the town"s population is composed of the under-18s.

B 選項應該改成consist of,The under-18s consist of nearly 25%of the town"s population.原句中的of 是nearly 25%of the town"s population中的成分.

C選項include是包括包含的意思，中文意思不符合題意.

D選項是正確的。