常见的连接词有though, although，as, while, even though
eg：Although/though he is a child, he can live by himself.
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 .
eg：He is experienced while he is young.
1.The anti-virus agent was not known
until a doctor find it by chance.
2.I would prefer shopping online to shopping in a department store because __________(它更加方便和省时)
it is more convenient and timesaving.
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.