1‘whether the temperature rise is due to the greenhouse effect is a moot point’
debatable, open to debate, open to discussion, arguable, questionable, at issue, open to question, open, doubtful, open to doubt, disputable, contestable, controvertible, problematic, problematical, controversial, contentious, vexed, disputed, unresolved, unsettled, up in the air, undecided, yet to be decided, undetermined, unconcluded
1‘the idea was first mooted in the 1930s’
raise, bring up, broach, mention, put forward, introduce, advance, present, propose, suggest, submit, propound, air, ventilate
We take a look at several popular, though confusing, punctuation marks.