The 3-letter sets below can become three 11-letter words by combining them, with a certain letter used as a connector. The same letter will be used to connect the words in each set; each set uses a different letter. Don’t change the order of the letters.

-1. ate, ate, boi, erp, gul, ibi, ist, ity, phi
-2. arm, ben, end, int, nce, nts, rse, rsp, vol
3. cea, ele, ity, mon, sly, ter, toa, tma, tro
4. acr, bit, cal, inh, mon, ons, ous, pur, tan
-5. cap, dis, ful, gas, ing, iva, omy, rec, rus

1. (L) boilerplate - gullibility - philatelist

That's how it's done!

2. (E) benevolence - intersperse - endearments

Well done, ob!

5. (T) captivating - distrustful - gastrectomy hi Pandie, another great puzzle

Good solve, manxie! I've been dragging out some oldies lately.

4. acr, bit, cal, inh, mon, ons, ous, pur, tan

(i) acrimonious, inhibitions, puritanical