Question 14: Authorities should warn people against ________ hazardous

Question 14: Authorities should warn people against ________ hazardous foods containing additives. Still better, perhaps, they shouldn’t allow such products ________ in the first place.

• A. to be using – produced
• B. having used – to produce
• C. using – to be produced
• D. being used – being produced

Warn sb against doing st: cảnh báo ai không làm gì
Allow st/sb to do st: cho phép ai/ cái gì làm gì