Lest, let alone in completing sentence in SSC & HSC

How to complete the uncompleted sentences using "lest" and "let alone"
lest অর্থ (যাতে -- না/পাছে ভয় হয় )
let alone অর্থ (তো দূরের কথা/প্রশ্নই আসে না)

lest in completing sentenceslet alonelest and should