托福閱讀長難句

Spiral galaxies are well supplied with the interstellar gas in which new stars form; as the rotating spiral pattern sweeps around the galaxy it compresses gas and dust, triggering the formation of bright young stars in its arms.

【子句拆分】

連接詞：in which
定語從句：In the gas new stars form.
連接詞：as
狀語從句：The rotating spiral pattern sweeps around the galaxy.
并列句1：It compresses gas and dust, triggering the formation of bright young stars in its arms.
并列句2：Spiral galaxies are well supplied with the interstellar gas.

【成分劃分】

定語從句：In the gas[狀語] new stars[主語] form[謂語].
翻譯：新的星球會(huì)在星際間的氣體中形成。
狀語從句：The rotating spiral pattern[主語] sweeps[謂語] around the galaxy[狀語].
翻譯：旋轉(zhuǎn)的螺旋型圍繞星系掃過。
并列句1：It[主語] compresses[謂語] gas and dust[賓語], triggering the formation of bright young stars in its arms[狀語].
翻譯：它會(huì)擠壓氣體和塵埃，從而在旋臂中促成明亮的年輕星球的形成。
并列句2：Spiral galaxies[主語] are well supplied[謂語] with the interstellar gas[狀語].
翻譯：螺旋形的星系被星際間的氣體很好地補(bǔ)給。

【全句翻譯】

螺旋形的星系被星際間的氣體很好地補(bǔ)給，新的星球會(huì)在星際間的氣體中形成；當(dāng)旋轉(zhuǎn)的螺旋型圍繞星系掃過的時(shí)候會(huì)擠壓氣體和塵埃，從而在旋臂中促成明亮的年輕星球的形成。

知識(shí)點(diǎn)梳理

這句話中的 triggering the formation of bright young stars in its arms 屬于動(dòng)詞ing形式作結(jié)果狀語， the rotating spiral pattern sweeps around the galaxy it compresses gas and dust 屬于原因，前后構(gòu)成因果關(guān)系。
例句：The song is sung all over the country, making it very popular.