Re: The weigh attach to the balloon is too light therefore, it raised/flew up with th
1 is how it sounds more natural to me. Others might find your originals okay.
Originally Posted by scott833
I'm not sure how I feel aout #2. At first I was doing to say that none of them worked. Maybe it's okay.
#3 is your best one, grammatically, though I am doubtful about it factually.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.