Reorder the sentences and write it, as it should be.
a.- be / fine / tomorrow. / should / It
b.- immediately./ the fire alarm, / their room / On hearing / hotel guests / should leave
c.- Passengers / departure time. / at least /check-in / before / 2 hours / should
d.- You / never / should/ your doctor. / lie to
e.- should / more attention / in class. / You/ pay
f.- at work / be/ should / You / before 9.