〖考点〗本题考查if条件句中的省略情况。

〖解析〗本句的句子的主语是the experiment；谓语动词是shows；that引导宾语从句, 宾语从句的主干事：proper amounts of exercise can improve our health, if_____ regularly是插入的条件从句, 从句的主语是proper amounts of exercise, 此时应用it代替前面提到的主语, 条件句的主语与主句的主语一致, 并且含有is, 故省略了it is, 完整形式是：if it is carried out。句意为：这项实验表明, 适当的运动, 如果有规律的进行, 能够有助于我们的身体健康。

4. Only when you can find peace in your heart _____good relationships with others.

A. will you keep B. you will keep C. you kept D. did you keep

【考点】考察倒装句

【答案】A

【解析】本题考察的是only的倒装句。当only放在句首，且强调的是状语的时候，需要使用部分倒装的形式。本题中only放在了句首，强调的是时间状语从句when you can find peace in your heart，所以后面的主句要使用倒装句。D项的时态错误。句义：只有当你取得内心的安宁以后，你才可以和别人保持良好的关系。故A正确。

5. Only if people of all the countries are united ________（我们才能解决）the existing problems in the world. (solve)

〖答案〗will we be able to solve/can we solve.

〖考点〗倒装句

〖解析〗only位于句首修饰状语从句要倒装。根据 "主将从现"的原则可以确认主句的助动词是"will", 或者使用情态动词"can"

6．Terry, please your cell phone when Grandma is talking to you.

　　A. look up from B. look into

　　C. look back on D. look through

【考点】考察动词短语词义辨析

【答案】A

【解析】动词短语look up 查找，抬头看；look into调查，研究；look back on回顾；回忆；look through仔细检查；看穿；句义：Terry，当奶奶和你说话的