Question 26. They finished one project. They started working on the next right away.

A. Hardly had they finished one project when they started working on the next.

B. Only if they had finished one project did they start working on the next.

C. Had they finished one project, they would have started working on the next.

D. Not until did they start working on the next project when they finished one.

Kiến thức: Câu đảo ngữ

Giải thích:

Only if + had + S + PII did + S + V2.

Tạm dịch:

Chỉ khi họ đã hoàn thành một dự án thì họ mới bắt đầu làm dự án tiếp theo.

Choose B.