1) But the obvious(fatal/serious) flaw (defect/drawback) in their argument (attitude/idea/view/action/behavior) is that.../But the basic (main/great/key/ big) problem with their argument (...) is that...
(e.g. ...that they are ignorant of (blind to) a bare fact: Social changes have attached new meanings and values to the division between good and bad.)
2) But if...it is (not) easy (difficult/hard) to see (find/discover) that ...
(e.g. But if they adjust their frame of mind a little in the other direction , it is not hard for them to find that life is just as promising as before.)
3) Too much emphasis (attention/stress/concern/significance) placed on (given to/focused on/attached to/paid to) the negative (sunny/gloomy/bright) side of the issue, however, may...(如mislead/confuse/cloud/bias/disturb our judgment of it.)A
(e.g. ..., however, may mislead us to form a pessimistic estimate of current situations.或..., however, may stop us from rendering (passing/forming/having) a fair(correct/clear/infallible/wise)judgment on it.)
4) But in most cases/from the point of view of justice (objectivity)/as a matter of fact/in a very true sense, their (public/general) satisfaction (dissatisfaction/disillusionment/concern) with...(或their criticism of.../their argument for/against.../their objection to.../their approval for...) can not.../is..., for...
(e.g. But in an impartial sense, the public dissatisfaction can not hold every water, for our society is still abundant in goodness and beauty.)
5) As a result of..., however, things would/are bound to...
(e.g. As a result of such an utter indifference to vicious behavior, however , things would be past saving/mending/all the hope.)
1) when, if, the other day in a certain place, suppose/imagine/assume (that...), in (the) course/time of...for instance, in the event of等;
2) in the case of, as for/to, as far as...is/are concerned, The same is t rue of..., when compared with, in comparison with, by comparison等;
3) If there is anything that comes close to/is comparable to/with...,...t here is hardly, a thing that compares favorable with/can rival...