By the time we arrived, they __________ (wait) for us for over an hour.

• had been waiting
• had waited
• were waiting
• waited

She __________ (study) for three hours before she took a break.

• had been studying

• Had been studying

When we met them last year, they __________ (live) in Paris for five years.

• had been living

• Had been living

By the time the train arrived, I __________ (stand) on the platform for twenty minutes. -had been standing คำตอบนี้ถูกต้องหรือไม่

They __________ (work) on the project for months before they finally completed it.

• had worked
• have been working
• has been working
• had been working

Before the teacher entered the classroom, the students __________ (talk) loudly.

• had been practicing

• Had been practicing

By the time we found the dog, it __________ (wander) in the forest for days.

• had been wandering

• Had been wandering

She __________ (wait) for the bus for half an hour before it finally arrived.

• had been waiting

• Had been waiting

By the time he decided to call her, she __________ (try) to reach him for hours. -had be trying คำตอบนี้ถูกต้องหรือไม่