Give equivalents to the wing words:

certain, necessary, operation, mountings, to protect, to fit, auxiliary, injecting, to enable, to position, to connect, to supply, device, rate, air vent, to insert.

Certain - definite, sure, reliable
necessary - essential, required, needed
operation - functioning, performance, activity
mountings - fixtures, fittings, supports
to protect - safeguard, shield, defend
to fit - install, fix, attach
auxiliary - supplementary, additional, secondary
injecting - infusing, introducing, administering
to enable - allow, facilitate, empower
to position - place, locate, arrange
to connect - link, join, attach
to supply - provide, furnish, give
device - gadget, tool, apparatus
rate - speed, pace, frequency
air vent - air duct, ventilation, air passage
to insert - place, insert, embed