【正确答案】 B

【答案解析】[解析] 画线词derive为动词，意为“得自，起源，引中于”，B项obtain意为“获得”；例：I haven"t been able to obtain that book anywhere.我到处都没能买到那本书。A项deprive意为“剥夺”，常和“of”连用；例：The new laws deprived many people of the most elementary freedoms.新法律剥夺了许多人最基本的自由。C项descend意为“下降”；例：The sun descended behind the hills.太阳下山了。D项trace意为“追踪，回溯”；例：The book traces the development of philosophy.这本书追溯了哲学的发展过程。