常见的连接词有though,although，as,while,eventhough
eg：Although/thoughheisachild,hecanlivebyhimself.
as表示虽然的时候，要进行倒装;
Childas/thoughheis,hecanlivebyhimself.
eg：Although/thoughsheworksveryhard,shemakesverylittleprogress.
Hardassheworks,shemakesverylittleprogress.
Although/thoughsheisyoung,shehastravelledtomanycountriestoputshows.
Youngassheis,shehastravelledtomanycountriestoputshows.
eg：Heisexperiencedwhileheisyoung.
真题分析：
1.Theanti-virusagentwasnotknown
untiladoctorfinditbychance.
2.Iwouldprefershoppingonlinetoshoppinginadepartmentstorebecause__________(它更加方便和省时)
itismoreconvenientandtimesaving.
3.Butsincewaterismuchcheaperthanwine,andmanyofthefancierbrandsaren’tavailableinstores,mostdinersdon’tnoticeorcare.
4.Whilethere’snoquestionthatcontinuousstressisharmful,severalstudiessuggestthatchallengingsituationsinwhichyou’reabletorisetotheoccasioncanbegoodforyou.
