Unrhyw syniad am be alla i ddeud am ‘flash in the pan’.

Y frawddeg, o ran cael cyd-destun yw:

‘We thought the Foundation would just be a flash in the pan, but it’s getting better all the time.’

Byddai unrhyw awgrymiadau’n cael eu gwerthfawrogi.

Diolch

Gwenllian