1.suppress
①If someone in authority suppresses an activity, they prevent it from continuing, by using force or making it illegal.
exp：...drug traffickers, who continue to flourish despite international attempts to suppress them.
②If a natural function or reaction of your body is suppressed, it is stopped, for example by drugs or illness.
exp：The reproduction and growth of the cancerous cells can be suppressed by bombarding them with radiation.
2.testify
When someone testifies in a court of law, they give a statement of what they saw someone do or what they know of a situation, after having promised to tell the truth.
exp:Several eyewitnesses testified that they saw the officers hit Miller in the face.
3.ambiguous
If you describe something as ambiguous, you mean that it is unclear or confusing because it can be understood in more than one way.
exp:This agreement is very ambiguous and open to various interpretations.
4.ascend
① If you ascend a hill or staircase, you go up it.
exp:Mrs. Clayton had to hold Lizzie's hand as they ascended the steps.
②If a staircase or path ascends, it leads up to a higher position.
exp:A number of staircases ascend from the cobbled streets onto the ramparts.
③ If something ascends, it moves up, usually vertically or into the air.
exp:Keep the drill centred in the borehole while it ascends and descends.
5.brisk
①A brisk activity or action is done quickly and in an energetic way.
exp:Taking a brisk walk can often induce a feeling of well-being.
② If trade or business is brisk, things are being sold very quickly and a lot of money is being made.
exp:Vendors were doing a brisk trade in souvenirs.
6.certify
①If someone in an official position certifies something, they officially state that it is true.
exp:The president certified that the project would receive at least $650m from overseas sources.
②If someone is certified as a particular kind of worker, they are given a certificate stating that they have successfully completed a course of training in their profession.
exp:They wanted to get certified as divers.
7.conceive
①If you cannot conceive of something, you cannot imagine it or believe it.
exp:I just can't even conceive of that quantity of money.
②If you conceive something as a particular thing, you consider it to be that thing.
exp:The ancients conceived the earth as afloat in water.
③If you conceive a plan or idea, you think of it and work out how it can be done.
exp:She had conceived the idea of a series of novels, each of which would reveal some aspect of Chinese life.
④When a woman conceives a child or conceives, she becomes pregnant.
exp:Women, he says, should give up alcohol before they plan to conceive.
8.contemplate
① If you contemplate an action, you think about whether to do it or not.
exp:For a time he contemplated a career as an army medical doctor.
②If you contemplate an idea or subject, you think about it carefully for a long time.
exp:As he lay in his hospital bed that night, he cried as he contemplated his future.
9.eccentric
① If you say that someone is eccentric, you mean that they behave in a strange way, and have habits or opinions that are different from those of most people.
exp:He is an eccentric character who likes wearing a beret and dark glasses.
10.essence
① The essence of something is its basic and most important characteristic that gives it its individual identity.
exp:The essence of consultation is to listen to, and take account of, the views of those consulted.
②If you say that something is of the essence, you mean that it is absolutely necessary in order for a particular action to be successful.
exp:Speed was of the essence in a project of this type.
③You use in essence to emphasize that you are talking about the most important or central aspect of an idea, situation, or event.
exp:Though complicated in detail, local taxes are in essence simple.
④ Essence is a very concentrated liquid that is used for flavouring food or for its smell.
exp:.a few drops of vanilla essence.
