sentence

[superbad.livejournal.com]

Is this more or less how you would say "If I lost my SIM card, can I keep my old number?"

При потери СИМ-карточки, можно сохранить старый номер?

(no subject)

[upthera44.livejournal.com]

Could you recommend some very common and useful expressions in Russian? Unfortunately, I've never learned very many idioms and expressions and would like to learn more. For instance, things like: 

делать из мухи слона

меньше знаешь, лучше спишь

одним ударом убить двух зайцев