Try these!
Or these?
How about these?
Easy-peasy!
Even easier!
100

area

*A*rea

100

idea

id*E*a
100

event

e*VE*nt

100

engine

en*GIN*

100

focus

*FO*cus

200

profile

*PRO*file

200

foreign

*FO*reign

200

japanese

*ja*panese

200

finite

*FI*nite

200

climate

cl*I*mate

300

electric

el*EC*tric

300

infinite

*IN*finite

300

amplifier

*A*mplifier

300

licence

*LI*cence
300

promise

*PRO*mis

400

determine

de*TER*mine

400

aeronautics

aero*NAU*tics

400

engineer

engin*EER*

400

electronic

elect*RON*ic

400

identifying

i*DENT*ifying

500

comfortable

*Com*ftable

500

environment

en*VIRE*ment

500

simultaneous

simul*TA*neous

500

developed

de*VE*loped

500

clothes

cl*O*thz