1.fervent a.强烈的，热烈的(passionate, zealous)

词根记忆：ferv(热)+ent一热情的--热烈的

注意：ferment(矿发酵)

例：The church members listened to their minister's fervent prayers.

派生词：fervently( ad.热烈地)

2.fetal a．胎儿的(of fetus)

词根记忆：fet(胎儿)+al一胎儿的

注意：fatal(a．致命的)

例：Using a Doppler ultrasound device, feta/heartbeats can be detected.

同根词：fetology(n.胎儿学)；feticide(n．堕胎)

3.fetch v.售得(to be sold for)

例：Individual bulls and cows received awards, fetched unprecedented prices, and excited enormous interest.

4.feudal a.封建制度的(of or according to the system during the Middle Ages in Europe, under which people receive land and protection from the landowner and work and fight for him in return)

词根记忆：来自feud(n.封地)

例：feudal landholders封建地主

派生词:feudalism(n.封建主义，封建制度)

5.fiber n.纤维(a thread or a structure or an object resembling a thread)

例：fier-optic cable光纤电缆

6.fibrosis n.纤维化(a condition marked by increase of interstitial fibrous tissue)

词根记忆：来自fibre(n.纤维)

例：When lung tissue from people with cystic fibrosis is maintained in a solution with a normal satt concentration, the tissue can resist bacteria.

派生词:fibrotic(a．纤维化的)

同根词：fibroid(a．纤维性的;纤维状的)

7.fickle a．易变的，不坚定的(unstable, unreliable)

词根记忆：fic(做)+kle--做得不坚决--不坚定的

例：a fickle fortune多变的命运

8.fierce a．残酷的(cruel)；凶猛的(violent)

词根记忆：和force(矿强制，强迫)一起记

例：fierce competition残酷的竞争//frerce struggle激烈的挣扎

派生词：fiercely(ad.猛烈地;很)