_______ by keeping down costs will Power Data hold its advantage over other companies.

Only  

Just 

 Still  

Yet

考查倒装句式。句意：只有通过降低成本，Power Data才能比其它公司更有优势。A只有；B仅仅；C仍然；D然而。Only加副词、介词短语或时间状语，放句首时，用部分倒装。故选A。

Don't forget            the letter for me when you pass  by the post office.

post

to post

posted

posting

考查不定式作宾语。句意：你经过邮局时别忘了替我寄这封信。forget to do sth忘记要做某事；forget doing sth 忘记做过某事。根据句意表示事情已经发生。故选B项。

--What is happening in that new area?

---New houses          over there.

are built

are building

have built

are being built

考查时态和语态。句意：在那个新区域里发生什么事情了？那儿建起来许多新的大楼。根据第一句时态is happening 可知，时态用现在进行时，故第二句也要用现在进行时，主语 houses与build 建立之间是被动关系，故用现在进行时的被动语态（am/is/are being done），此处为are being built，故选D项。

He punished the children          their carelessness         making them pay for the damage.

by; for

with; by

for; by

about; with

考查介词。句意：他因为孩子们的粗心惩罚他们赔偿损失。根据句意可知：“their carelessness"表示他们被惩罚的原因，需用介词for表原因。"making them pay for the damage"表示他们被惩罚的方式，需用介词by表方式。故选C项。

I would really appreciate       if you can make time in your schedules to attend my lecture today.

that

it

this

one

考查形式宾语。句意：如果你今天能从日程安排中抽出时间来听我的讲座的话，我将不胜感激。I would appreciate it if/when...如果/当...时，我将非常感激。it 做形式宾语。故选B项。