The main factors of extracting flavonoid were also studied.是什么意思？

The main factors of extracting flavonoid were also studied.

讨论了影响黄酮提取的主要因素.

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

main

adj. 主要的，最重要的，全力的；n. 最主要的部分，重点，主要管道，体力，[航海]公海；

例句
The school occupies split-site accommodation on the main campus...
该学院分散在主校区不同地点。

factors

n. 因素( factor的名词复数 )，<数>因子，（增或减的）数量，系数；

例句
Forster established the essentiality of minerals as accessory food factors required for maintaining life.
福斯特证实了矿物质作为辅助食物因子在维持生命方面的重要性。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

extracting

n. 萃取，提取，提

例句
OBJECTIVE To search for the best technique for extracting polysaccharide from Thelenota ananas.
目的优选梅花参中梅花参多糖的提取工艺.

flavonoid

n. 类黄酮；

例句
In printing ink antogenous ( chloridizing polypropylene ), benzene, ginkgolide - flavonoid solvents are true solvents.
在复合里印油墨中 ( 氯化聚丙烯型 ) 苯类、酯类 、 酮类溶剂都为真溶剂.

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

also

adv. 也，同样，并且；conj. 另外；

例句
The media have also abetted the feeling of unreality.
媒体也在一旁对这种非现实感推波助澜。

studied

adj. 有计划的，故意的，深思熟虑的，精通的；v. 学习，研究( study的过去式和过去分词 )，想出，详细地检查，背诵（台词等）；

例句
At college he studied English and did amateur boxing.
大学时，他学习英语，同时还参加业余拳击。