點解一句英文會有咁多動詞?

What is answer-001 talking about?

It is definitely something not related to the questions, and there are some blind-voters.

This is a simple sentence structure.

This bloody lesson, together with the frequent publicity during the period when the
law first came into effect, led to a large drop in the number of drink-driving accidents in recent years, with the number of fatal accidents for two consecutive years falling to zero.

[subject], [apposition], [main verb] [prepositional object], [prepositional phrase - adverbial].

note: apposition has to be offset with commas

Verbs:
came - the main verb (finite) of the relative clause "when the law first came into effect"
led - the main verb (finite) of the sentence (main clause)
falling - the verbal / participle (non-finite) of the prepositional phrase

2014-10-24 15:42:46 補充：
Example: a sentence with same structure

My mother, as well as my brother, listened to music with headphone, with the nearby construction site making tedious noise.

呢句係倒裝句。
咁長好難睇，現設 "things reached fever pitch" 為 X，"the constraints they work under" 為 Y：

Only after X did the factories allow the foreign press in to see Y.

其實倒裝句只係將想強調o既資料放最前，吸引人注意。而 did 就好似問問題時加個 do 咁，tense 或第三身單數o既變化都去左 do 度。所以全句正常次序可以改寫成：

The factories allowed the foreign press in to see Y only after X. =>

The factories allowed the foreign press in to see the constraints they work under only after things reached fever pitch.

即「這些工廠在事情鬧得熱烘烘之後，方才容許外國傳媒一窺他們工作的限制。」

老實講，倒裝句唔係重點要學o既句法，因為較深，日常唔多見／用（除 so do I/ neither can I 等常用短句），多用則變得做作。

* * *

句中有多過一個動詞，係因為呢句係複句，當中包含不同句子，不足為怪。講時間、條件（when/while/before/after/if）時都成日用到（如 I won't go if you don't come out）；而後面 the constraints they work under 其實係 defining relative clause，可以睇作 the constraints which they work under。

你打漏標點，應該係咁

This bloody lesson, together with the frequent publicity, during the period when the
law first came into effect, led to a large drop in the number of drink-driving accidents in recent years, (while) the number of fatal accidents for two consecutive years falling to zero.