1) "If eyelashes are long, they must be fakes"? (5,9) I think it's F?L??, ?E?????N? 2) Joined in the drive to boost employment? (4,1,4) T???, A, ?A?? 3) Plenty of opportunity to crack the codes in a stroke. (4,5) W???, ??O??
I think a poor clue for a cryptic crossword as it is simply a statement of an incorrect assumption which is therefore non sequitur, an alternative expression for which is given in the dictionary as 'false reasoning'. I can't see any alternative way of getting to the answer