[lojban-beginners] Asking specific questions

[Ian Johnson <blindbravado@gmail.com>]

Today I asked my lab instructor:
So we're testing with methanol twice? 
(The emphasis in text is stronger than it actually is in voice, but you get the idea). In other words, I knew we were testing with methanol, was pretty sure we were doing it twice, but was not 100% sure about the twice part. This intuitively seems somewhat similar to a {ma} question (more so than many other English questions), in that you basically state an ordinary sentence but are asking someone to fill in a blank. However, you also have a guess. This means that if "we're testing with methanol twice" is true, then the answer should be "yes" (maybe "yes, twice"), but if "we're testing with methanol once" is true then the answer should be "no, once." 

Does Lojban have an analogous "fill-in-the-blank or verify that my filling is correct" mechanism? If so, how do you use it? My guess was (if there isn't a specific mechanism for this) that you would use a combination of a connective question and another question word, making a possible structure of:
do <selbri> <x2 sumti> ji ma
(I can't think of a specific example here for whatever reason, and my example above is probably somewhat beyond my level for other reasons). 
Would this work?

mu'omi'e latros.