All of the following measure mass in the si system except
grams
liters
kilograms
milligrams

The answer is liters, liters is for liquid/fluids 

Liters, liters are for measuring liquids, and this is more of a science question than it is English. :) 

It could be 1, 2, or 4, depending on the context.1.) they could have had a fight, and she is too humble to say anything further. she wants robert to say something first.2.) maybe he's staring at a computer playing tetris while she's wearing a *really* tight red dress. just sayin' xd3.) is unlikely given that it's only one sentence worth of context long. 4.) it's possible their relationship is more 'mutual hatred' and they tolerate one another.it could be 1, 2, or 4, as long as you can provide sufficient explanation why. remember this as you write!