Match up the words which are similar in meaning:

purpose, in the sphere of, to make, important, aim, proper, common, to work out, to vary, time, in the field of, significant, ray, to define, to operate, to develop, to differ, to show, method, to function, to demonstrate, technique, device, to determine, standard, to produce, suitable, beam, period, instrument.

purpose - aimto make -to producebeam -  raytime - period, to work out, -  to operate, to define -  to determineto show, - to demonstrate important,  - significantdevice, -  instrument. proper - suitable,common - standard,  to vary - to differ,  in the sphere of, - in the field of, to develop, - to functiontechnique,  - method