IN THE BEDROOM Dont smoke in bed—it causes about 1 000 fires a year, many with fatal

results. Dont overload your electrical points; the ideal is "one appliance, one socket". Dont use an electric underblanket over you or an overblanket under you. An underblanket, unless of the low voltage type, MUST be switched off before you get into bed. Never let furniture or clothing get close to a lighted fire. Make sure that there is a suitable guard for the room heater. Keep aerosol type containers (喷雾器) away from heat and NEVER burn or puncture (刺穿) them. Dont dim a table lamp by covering it: buy a low wattage bulb. Pyjamas and nightdresses, especially for children and elderly people, should be made from flame resistant material. IF CUT OFF BY FIRE Close the door of the room and any fanlight or other opening and block up any cracks with bedding, etc. Go to the window and try to attract attention. If the room fills with smoke, lean out of the window unless prevented by smoke and flame coming from a room below or nearby. If you cannot lean out of the window, lie close to the floor where the air is clearer until you hear the fire brigade. If you have to escape before the fire brigade arrives, make a rope by knotting together sheets or similar materials and tie it to a bed or another heavy piece of furniture. If you cannot make a rope and the situation becomes intolerable, drop cushions or bedding from the window to break your fall, get through the window feet first, lower yourself to the full extent of your arms and drop. If possible drop from a position above soft earth. If above the first floor, drop only as a last resort

According to the instructions, fires in the bedroom can be caused by______.

A．one appliance, one socket

B．smoking in bed

C．underblankets of the low voltage type

D．all of the above mentioned points