常見的連接詞有though, although，as, while, even though
區(qū)分though，although，as
eg：Although/though he is a child, he can live by himself.
as 表示雖然的時(shí)候，要進(jìn)行倒裝;
Child as/though he is , he can live by himself.
eg：Although/though she works very hard ,she makes very little progress.
Hard as she works, she makes very little progress.
Although/though she is young, she has travelled to many countries to put shows .
Young as she is, she has travelled to many countries to put shows .
while：連接兩個(gè)句子，表示雖然，但是;
eg：He is experienced while he is young.
題分析：
1.The anti-virus agent was not known
(直到一名醫(yī)生偶然發(fā)現(xiàn)了它)
until a doctor find it by chance.
2. I would prefer shopping online to shopping in a department store because __________(它更加方便和省時(shí))
It is more convenient and time saving.
3.But since water is much cheaper than wine, and many of the fancier brands aren’t available in stores, most diners don’t notice or care.
4. While there’s no question that continuous stress is harmful, several studies suggest that challenging situations in which you’re able to rise to the occasion can be good for you.
