however 与 yet的区别

however 与 yet的区别
How is he getting on with his job hunt?--He was looking for a suitable job all the time,__ he has failed.
A.when B.however C.yet D.since

区别:They are similar in function,as they usually introduce a clause that
contradicts the previous one.Which you choose is largely a matter of
style.
Consider:
(a)The sky was clear but it rained
(b)The sky was clear yet it rained
(The latter (b) suggests an element of surprise at the outcome,which the first does not.)
[1]however:used with an adjective or adverb to mean ‘to whatever degree’:
a)He wanted to take no risks,however small.
b)She has the window open,however cold it is outside.
c)However carefully I explained,she still didn’t understand.
[2]yet:used in negative sentences and questions to talk about sth that has not happened but that you expect to happen:
a)British:I haven’t received a letter from him yet.
b) American:I didn’t receive a letter from him yet.
c)‘Are you ready?’ ‘No,not yet.’
d) We have yet to decide what action to take (= We have not decided what action to take).
[2a](used in negative sentences) now; as soon as this:
Don’t go yet.
We don’t need to start yet.
[2b]from now until the period of time mentioned has passed:
He’ll be busy for ages yet.
They won’t arrive for at least two hours yet.
[2c]could,might,may,etc.do sth used to say that sth could,might,etc.happen in the future,even though it seems unlikely:
We may win yet.