highly likely
highly probable

Also a theory on this matter occurred to me, which seems to be highly probable.

At any rate it seemed highly probable that they had souls.

Unless you get under cover pretty soon, this becomes highly probable, my friend.

"It's highly probable we will have to pay for our sins after life on earth."

This seemed highly probable when the door handle started to turn.

It seems highly probable to me that this guy is in the employ of the Iranian government.

It's highly probable that there are duplicates of the whole lot but never mind.

The discovery of the tomb by women is highly probable.

If things go wrong, which is highly probable, you shouldn't be in the area.

It is highly probable that other chemicals will be used.