1.additional a.附加的,另外的
例句：This additional work is relative to the current project.
这追加的工作是有关目前的计划。
2.involve vt.包缠;使卷入,使陷入;使专注;必须包括;包围
例句：Don't involve other people in your trouble.
别把别人牵涉进你的麻烦中去。
The demonstration involved about 20 000 students.
这次示威包括约两万学生参加。
3.placebo n.为死者所诵的晚祷歌,宽心剂,安慰
4.inactive a.不活动的,停止的,怠惰的
例句：Illness forced him to live an inactive life.
疾病使他的生活没有生气。
5.breakthrough n.突破,突破性进展
例句：The deaf were hoping for a breakthrough in science that could allow them to hear.
耳聋的人们都希望科学上有所突破使他们能够听到。
6.sponsor v.发起,赞助,倡议
例句：The company sponsored several TV programs.
这家公司为几个电视节目提供了赞助。
7.lower v.放下,降下,放低;减低
例句：The Government won't lower the age limit to buy alcohol.
政府不会降低对买酒者的年龄限制。
8.combination n.组合,合并,联合
例句：The risk of flooding has been increased by a combination of factors.
产后出血的危险性因一系列因素而增加了。
9.nonprofit a.非营利的,不合资本主义的
例句：The funds of nonprofit organizations are nontaxable.
非盈利性机构的资金是免税的。
10.continual a.持续不断的,继续的
例句：The noisy traffic is a continual annoyance to the citizens.
城里的交通噪声总是使城市居民烦恼。
1.The researchers say that was compared with only fifty-one of those who received the vaccine.
compare with比较…,跟…相比,比得上…
例句：Few writers can compare with Scott as creators of romance.
能与史考特匹敌的罗曼史作家并不多。
Living in a city can’t compare with living in the country.
在城里生活无法同在乡村生活相比。
2.The study was based on versions of H.I.V. commonly found in Thailand.
be based on以…为基础,以…为根据
例句：The valuation of fixed assets shall be based on the original cost.
固定资产的计价，应当以原价为准。
The building of national defense should be based on economic strength, science, and technology.
国防建设要有强大的经济实力作基础，高端的科技水平作后盾。
3.But, they warn that persons with weakened defenses for fighting disease are at greater risk.
at risk在危险中,在危急时
例句：The whole future of the company is at risk.
这家公司的整个前途都处在危险之中。
They say the levels of Mycobacterium avium were one hundred times higher than that of normal household water.
倍数的比较
表示三以上的倍数用times，但表示两倍（汉语中的一倍实际上也指两倍）时则用twice, double, duple, twofold, as…again as表示。译为
“翻一番”或“为…的两倍”。3倍常用three times, triple, threefold表示，译为“增加2倍，增至三倍”或“为…的3倍”。4倍用
quadruple，基数词＋times，基数词＋fold表示，译为“增加3倍，增至4倍”或“为…的4倍”。例如：
He earned double the usual wage in holiday. 他在假期里挣了比平时多1倍的工资。
This bridge is as long again as that bridge. 这座大桥的长度是那座大桥的2倍。
They have produced four-fold as many laptops as they did last year.他们今年生产的笔记本电脑相当于去年的4倍。
Their grains have trebled (tripled) this year. 他们的粮食今年增加了2倍（是…的三倍）。
1) 主语+谓语+ X times + as + adj. + as
这个句型译为：① A…是B的X倍（或净增加X－1倍）.
例如：This pen (A) is twice as expensive as that pen (B).
这只钢笔(A)的价格是那只钢笔(B)的2倍。（即A比B贵一倍）
I have three times as many as you. 我有你三倍那么多。（我的比你的多两倍）
This box is four times as heavy as that box. 这个盒子比那个盒子重4倍。
2）主语+谓语+ X times+ the size (amount, width, breadth, level, value, velocity, length…) of…
这个句型表示净增加“1倍，是…的2倍”例如：
The earth is 49 times the size of the moon. 地球是月球大小的49倍。
3）主语+谓语+ X times + 形容词（副词）比较级+ than…
这个句型表示的数为净增加数。例如：
The grain output is one time higher this year than that of last year.
今年比去年粮食产量增加一倍。
4）还可以用by+倍数，表示增加多少倍
The production of grain has been increased by four times this year.
今年粮食产量增加了4倍。
注意: 倍数表达法的几点注意事项
1) 增加
倍数的增加
increase by 5 times 增加了5倍
increase 5 fold (times) 增加到5倍
increase by a factor of 5 增加4倍
multiply 5 times 增加到5倍(增加了4倍)
4 times as great as 为…的四倍
4 times more than 比…多四倍（增加了5倍）
twice as long as 两倍于（比…长1倍）
2）减少
倍数的减少
decrease by 20% 减少了20％
decrease to 20% 减少到20％
decrease by a factor of 5 减少了4/5（减少到1/5）
decrease 3 times 减少到1/3(减少了2/3)
twice less than 为…的1/3 (比…减少2/3)