_______(safe)needs to be improved on the railways in that country

Not until recently_____that Thompson had ben telling the truth all along

Ifyouhadbeeninbetterhealth,we___(allow)youtojointheminthework.

I'd appreciate it very much if you could make some ________on my recent article at the conference.

In August 1977, a satellite to gather data about the 10 million black holes which are thought to be in the Milky Way.