Now one of the most serious problems many people are worried about _____ on the lack of adequate housing space.
It was__ he said__ disappointed me.
If you want to do the experiment again, you had better be more careful_______ you made a mistake.
------ He should have been warned of the danger. ------_________, but he wouldn’t listen to me.
______ a mobile phone can you ring _____ you want to talk with anywhere.
We don’t doubt ____ he’ll give us much help. _____ we doubt is _____ he’ll come on time