1.fivefold a./ad.五倍的(地) ( being five times as great or as many )

例：He repaid the loan fivefold,

2.fixture n.[常pl.]（房屋等的）装置，配置( something that is fixed or attached in a building as a permanent appendage or as a structural part)

例：I installed a new light fixture above the kitchen sink.

3.fjord n.峡湾（尤指挪威海岸边的）(bay, gulf)

词根记忆：和lord(n.地主)一起记

4.flat a．平滑的(having a smooth, even, level surface);（收费）统一的(having a single price for a variety of goods or services)；固定的(fixed)；n.公寓( an apartment on one floor)

例：Those plastic beverage containers can be crushed completely flat by refuse compactors.//Property taxes are typically set at a flat rate per $1,000 0f officially assessed value,

派生词:flatly( ad.水平地，平平地)

5.flatten v.变平(to become or make sth. flat);彻底打败某人（to defeat sb. com- pletely）

词根记忆：来自flat(n.平面；a．平坦的)

例：Jazz singer Billie Holiday used her voice in the same way that other musicians use their instruments, in that she ranged freely over the beat, flattening out the melodic contours of tunes.

同根词：flatness(n.平坦;单调)

6.flaunt v.炫耀，夸耀(to display or obtrude oneself to public notice)

例：Designers have adopted a cornerless style of smooth surfaces and curves that is more ergonomic, conforming to the shape of the body rather than flauntincj shape for its own sake.

7.flavor n.风味(the blend of taste and smell sensations)；香料(spice)

例：The bread had a more delicate flavor because it was not toasted.//flavor additives香料添加剂

8.fledgling n.雏鸟(nestling)；a．新兴的(inexperienced, new)

词根记忆：和fledge(v.长羽毛)、fledged(a．羽毛长成的，成熟的)一起记

例：fledgling sea eagles雏海鹰//fledgling industries新兴产业