____ what may, we’re not going to make any concessions to his unreasonable demands.

You’dbettersing.Itdoesn’t______whetheryoucansingwellornot.

He concluded his speech with a remark that failure ____the mother of success.

It’s necessary ______ us to keep our pets clean everyday.

You ’d better sing. It doesn’t ______ whether you can sing well or not.