超碰免费人人操|国产视频二区久久艹人人操|欧美激情第一页在线|久热最新无码中文视频|91精品国际成人|亚洲成人精品在线视频青青草|久草免费高清完整在线观看|你懂的AV在线日本黄网页|国产黄色AV日韩女同网|欧美成人色区导航片av

иxLy

r(sh)g2021-01-09 18:52:54 иԇ ҪͶ

P(gun)иxLy

иxLyұg(sh)l(f)չ

P(gun)иxLy

Unlike in the Americas, where metallurgy was a very late and limited development, Africans had iron from a relatively early date, developing ingenious furnaces to produce the high heat needed for production and to control the amount of air that reached the carbon and iron ore necessary for making iron. (50)

~R

metallurgy n. ұ (g(sh),W(xu))

ingenious  adj.

1(ָ) Ļ򺆆εķQ(f)s}`ɵ

2(ָ)O(sh)Ӌ(j)(d)ضɵ

3(ָ)eIJõ,

furnace  n. ۠t

һ(run by steam) ^Z(dng)~printing pressesע@run^Z(dng)~Ǻfound@׻

ģͨ^\(yn)

(by hand)~Zprinting pressesעrather than(j)lZ֮ǰҲ^һ(g)~ǡ

ģͨ^

(to produce a thousand pages in anhour rather than thirty.) ^Zitָ@`(ni)

ģa(chn)һǧ?jin)һ(g)Сr(sh)(ni)ҪʮСr(sh)

ɣoperators found it possible

g

һ(Unlike in the Americas),~Z

ģ

(where metallurgy was a very late and limited development) ,ľ

ģұg(sh)l(f)չdz

(developing ingenious furnaces) ,^Z(dng)~

ģl(f)չ˪(d)ضɵ۠t

ģ(to produce the high heat neededfor production),^Z(dng)~

ģɮa(chn)ұFҪĸߜ

壺(to control the amount of air) ,^Z(dng)~

ģƿ՚Ĕ(sh)

( that reached the carbon and ironore) ľair

ģ|̼FV

ߣ(necessary for making iron. ) ~Zair

ģ(du)ұFбҪ

ɣAfricanshad iron from a relatively early date

g

ұg(sh)l(f)չdzޓF^l(f)չ˪(d)ضɵ۠tɮa(chn)ұFҪĸߜҿƽ|̼FVĿ՚ԝMұFҪ

Сc(din)u(png)

@(g)ӵҪɷ־Ƿ^Z(dng)~~ZԼľ䣬҄(w)ÿһ(g)ɷʲôܿ@(g)ӵĽY(ji)(gu)

P(gun)иxLy䡿P(gun)£

иxLy08-15

иxLy07-15

P(gun)SATxLyͷ11-26

xиxеLy08-18

иxLy侚(x)q̫07-15

ӢZLy侫x11-26

2017иͻxLyk08-14

SATxLyc(din)06-19

2017иP(gun)ϵLy䌣}08-18