Question 12: In designing a new product, it is important ________ the

Question 12: In designing a new product, it is important ________ the production process carefully, as a mistake discovered later on can be expensive ________.

• A. having planned – rectify
• B. to be planning – rectified
• C. to plan – to rectify
• D. plan – to be rectified

- to be important to V: quan trọng để làm gì. 
- Cấu trúc: It + be + adj + (for O) + to V.