----I have tried very hard to find a solution to the problem, but in vain -

---why not consult with Frank? You see, _________.

A． great minds think alike

B． two heads are better than one

C． a bird in the hand is worth two in the bush

D． it’s better to think twice before doing something

[单选题]I tried hard, but I couldn’t find the _____to the problem.A.solutionB.helpC

I tried to persuade him to work hard, but with little _.A. effectiveB. effective

Though the firefighters tried very hard to _______ the fire，it still caused at l

They know their parents love them and have done much for them, but they find it

They know their parents love them and have done much for them, but they find it

I find this treatment very ____________ to my health．（ ）A. advisableB. invaluabl

They know theft parents love them and have done much for them, but they find it

They know theft parents love them and have done much for them, but they find it

The ___ is very hard. I cant answer it.A. questionB. matterC. problem

So much had changed, so many things had been______, and we tried so very hard to