Had the victim ____ able to find a telephone to contact authorities, she would have received assistance.

• Third conditional এর নিয়ম অনুযায়ী Sub-ordinate clause টি past perfect tense এর হলে principal clause টি perfect conditional (subject + would have/ could have/ might have + verb এর past participle) হয়। 
- এখানে Sub-ordinate clause টি had দ্বারা শুরু হয়েছে। 
- Sub-ordinate clause 'had' দ্বারা শুরু হলে, Had + subject + verb এর past participle হয় এবং principal clause টি perfect conditional হয়। 

Complete Sentence: Had the victim been able to find a telephone to contact authorities, she would have received assistance. 

Source: Advanced Learner's English Grammar & Composition by Chowdhury & Hossain.