Scientists have spent years______ into the effects of certain chemicals on the h

游客2025-04-03 30

问题 Scientists have spent years______ into the effects of certain chemicals on the human brain with no results.

选项 A、studying
B、investigating
C、inspecting
D、researching

答案 D

解析

转载请注明原文地址:http://tihaiku.com/zcyy/4025446.html

相关试题推荐

随机试题

最新回复(0)

Certainlypeopledonotseemlessinterestedinsuccessandwhatitcandof