can somebody explain me why is it "bemászik"? i wrote átmászik as i learnt it...
"Be", here, is referring the room. Into the room. "Through" (the window) is understood.
I can refer you to the reverse exercise where this sentence is discussed in detail:
I was allowed "kicsi" but not "kis". Is there a significant difference between the two or is this an oversight?
Both kicsi and kis are good here. (And now both of them are accepted)