Что надо вставить? You .... really be sitting here. a.) couldn't b.) shouldn't You .... be older than me, but that doesn't

You .... really be sitting here.

a.) couldn\'t b.) shouldn\'t - в значении \"не следует лучше не\";

You .... be older than me, but that doesn\'t mean you\'re cleverer.

a.) could b.) may - в значении \"можешь, мог бы\";

I\'m afraid that nobody ... help me in that kind of situation.

a) should b) would - в значении условного наклонения \"бы\" - \"помог бы\".