例句與造句

1. Rubber tree ( hevea brasiliensis ) is an important economic woody - crop in tropical areas . its latex is the unique source of crude rubber used in current industry . because of its special and important use , the rubber tree has been extensively planted in tropical areas . increase production is always the main target in rubber tree cultivation . since the ethrel was applied in increasing latex production in 1968 for the first time as a chemical stimulant , not only the latex production had been increased largely , but also a new set of rubber tapping system had been established , leading to a series of economic benefit . owing to ethrel " s extensive application , its side effects had been found more and more obviously , such as tapping dry , speeding up senescence , shortening the life span of rubber tree etc . in order to overcome the side effects and increase production more availably , for a long time , people had carried out lots of research work on cell level , membrane level , physiology and biochemistry of laticifer contents . but the mech anism why ethrel increased latex production was not yet understood completely . this study had cloned the ethylene receptor gene ( efrl ) from rubber tree , and researched the relationship between etrl expression in laticifers and ethrel stimulation on transcription level and protein translation level . the results were as follows : 1
   但是，由于乙烯利應(yīng)用的普及，乙烯利刺激割膠引起橡膠樹發(fā)生死皮病及加速膠樹衰老，縮短膠樹壽命等副作用也越來越明顯。為了克服這些副作用，使乙烯利能更有效地刺激增產(chǎn)，長期以來，人們在細(xì)胞水平、膜水平和乳管細(xì)胞內(nèi)含物的生理生化層面上進(jìn)行了大量的研究，但仍未完全了解乙烯對膠樹的作用機(jī)制。本研究從分子水平入手，克隆橡膠樹的乙烯受體基因( etr1 ) ，并在轉(zhuǎn)錄水平和蛋白質(zhì)翻譯水平上研究etr1基因在乳管細(xì)胞中的表達(dá)及與乙烯刺激的關(guān)系，取得了以下結(jié)果： 1
2. It's difficult to find source of crude in a sentence. 用source of crude造句挺難的