only作状语位于句首,主句的谓语用什么时态?

Only 做状语放句首,句子半倒装,谓语用单数,时态不一定,要看句子的时态.如：Only when I lost her did I realise how much I loved her.知道我失去她,我才发现自己有多爱她.Only by making efforts can we get high m...