Read the following leaflet and mark the letter A, B, C, or D to indicate the correct option that best fits each of the numbered blanks from 1 to 6.

Ways to Improve Air Conditioners

Below are several recommendations for using air conditioners more effectively during severe heatwaves.

1. (1) ______ temperatures at 26-28 °C: Experts advise keeping units at 26-28 °C to balance cooling comfort and operating efficiency. Lower settings, (2) ______ force air conditioners to run continuously at maximum power, increase the risk of overload and mechanical damage.

2. Combine fans with AC: Fans should operate while the air conditioner is on to help distribute cool air more evenly. The combination can reduce pressure (3) ______ the air conditioner and improve cooling efficiency during extreme heat.

3. Avoid running AC all day: Even during prolonged heatwaves, users are advised (4) ______ air conditioners short breaks after every four to six hours of operation. Turning the unit off for about an hour and opening windows to ventilate the room before restarting it can help extend the system's (5) ______ and reduce strain on the equipment.

4. Reduce heat entering the room: Experts recommend installing thick light-blocking curtains and keeping them closed during the day, especially in apartments (6) ______ to direct sunlight.

(Adapted from https://e.vnexpress.net/)