Choose from the options lettered A - E the one that most appropriately completes each sentence My friends were…

Analyze the question

The sentence is: "My friends were lucky __ the scene before the accident happened." We need the correct verb form after the adjective "lucky".

Explain the concept

After adjectives like lucky, glad, happy, sorry, we normally use an infinitive (to + verb). The tense of the infinitive depends on timing:

• Simple infinitive (to leave): the action happens at the same time as, or after, the main verb.
• Perfect infinitive (to have + past participle): the action happened before the time of the main verb or before another past event.

Step-by-step solution

1. "Were lucky" needs an infinitive, which rules out A ("they have left"), because it creates a clause with no linking word.
2. C ("to had left") is ungrammatical, since "to" is never followed by "had".
3. B ("to be leaving") suggests an ongoing action, which doesn't fit the meaning.
4. The leaving happened before the accident. That is an earlier completed action, so the perfect infinitive fits best: to have left.
5. E ("to leave") is grammatically possible, but it is less precise because it doesn't show that leaving came before the accident. D is the best fit.

Complete sentence: My friends were lucky to have left the scene before the accident happened.

Answer: D. to have left

Exam tip: When you see "before" or "after" in a sentence and the action is clearly earlier, look for the perfect infinitive (to have + past participle). Also, instantly eliminate any option with "to had", as it is always wrong.