B ……………… C ……………… E ……………… F
a bep eil …….. bob yn ail …… alternately …… tour à tour
eskemm ……. cyfnewid …….. exchange ……. échange
hanterour …… canolwr ………. go-between …. intermédiaire
leti, ostaleri … llety, gwesti …. hotel, inn ……. relais, auberge
relae …………. relái …………… relay …………. relais

(The last line is, of course “relay” in the technical, electronic sense.)

Re “avoir plusieurs cordes à son arc”: I think this is “to have a number of strings to one’s bow” rather than “to have many tricks up one’s sleeve”.

With the latter, you’re perhaps thinking of “to have more than one trick up one’s sleeve”, which I’d say is better represented in French by “avoir plus d’un tour dans son sac”, “avoir plus d’un lapin dans son chapeau” …or even “avoir plus d’un truc dans sa manche”!

tad
tad-kozh
tad-iou

mamm
mamm-gozh
mamm-iou

E – lifebuoy
C – bwi achub
B – boue saveteiñ
F – bouée de sauvetage

E – life jacket
C – siaced achub
B – jiletenn-saveteiñ
F – gilet de sauvetage

E – life raft
C – rafft achub
B – radell saveteiñ
F – radeau de sauvetage