experiment
[(1) to test; (2) a test or trial carried out to prove if an idea is true or false, or to discover something]
The candidate said he experimented with marijuana when he was a student. (1)
The medical experiments showed that the new medicine was not effective against cancer. (2)
expert
[a person with special knowledge or training]
She is an expert on nuclear disarmament.
explain
[(1) to give reasons for; (2) to make clear; (3) to tell about; (4) to tell the meaning]
Linda explained to her father why she wanted a big wedding. (1)
The president explained in detail his plan to send American soldiers to the troubled area. (2)
Wyatt explained the steps he used to solve the budget problem. (3)
Justin was asked to explain the effects of his solution on all sides in the dispute. (4)
explode
[to break apart violently with a loud noise, like a bomb]
The criticism made him explode in anger.
explore
[(1) to travel in a place that is not well known to learn more about it; (2) to make a careful search; (3) to examine closely]
A team led by Meriwether Lewis and William Clark explored the land west of the Mississippi River almost two hundred years ago. (1)
The spacecraft explored the solar system to search for signs of life. (2)
The committee explored every possibility before deciding what to do. (3)
export
[(1) to send to another country; (2) something sent to another country, usually for sale]
The United States has been importing much more from Asia than it exports. (1)
But it expects exports will increase following the approval of full trade relations with China. (2)
express
[to say clearly]
He expressed his love for her.
extend
[(1) to stretch out in area or length; (2) to continue for a longer time]
The rebels have extended their control over more of the country. (1)
Officials have extended the time that students must be in school each day, from seven hours to eight. (2)
extra
[more than normal, expected or necessary]
Newspapers printed extra copies to report election results.
extreme
[more than the usual or accepted]
My broken leg was extremely painful.
(～ly adverb)
extremist
[a person with strong religious or political beliefs who acts in an extreme or violent way]
Animal rights extremists broke into the building and released all the laboratory animals.
编辑推荐：大学英语四级/cet4词汇带英文注释汇总
From:https://www.zgghmh.com/CET-4/20002901.asp