Pressure Cooker ( 压力锅 ) Safety When you are cooking with a pressure cooker, you should learn a fewcommon sense ( 常识 ) rules: 1. Never leave the cooker unwatched when it is in use. 2. Add sufficient liquid but never past there commended fill point. Overfilling the cooker may block the vent pipe ( 排气孔 ) and cause the cooker to explode. 3. Set the cooking time. Too much time may overcook the food or too much pressure may build up in the cooker. Too little time will lead to undercooked food. 4. If you are new to pressure cooking,follow the cooking instructions carefully. Heat and time can either result in a great meal or a ruined one. 5. Never try to force a pressure cooker cover open. Allow the cooker to cool or run it under cool water before trying to open the coven. 6. Clean the cooker thoroughly after each use. Mild detergent ( 洗涤剂 ) and hot water work the best. Do not use stove ash or sand for they may damage the cooker.The gasket ( 密封圈 ) is best cleaned in warm soapy water and then dried. Store the gasket inthe bottom of the pot. 21. According to the first rule, the user should _________.