题目

下列调查活动或实验中，实验所得到数值与实际数值相比，肯定偏小的（ ） A . 标志重捕法调查池塘中鲤鱼的种群密度时，部分鲤鱼身上的标志物脱落 B . 探究培养液中酵母菌种群数量时，从试管中吸出培养液计数前没有震荡试管 C . 调查土壤小动物丰富度时，用诱虫器采集小动物没有打开电灯 D . 样方法调查草地中的蒲公英时，统计正好在样方线上的所有个体Everyone needs to know how to prevent a fire. It is also important to know what to do when it 1.break)out.Every year, over 11，000 people 2.(kill)or injured in house fires. These fires could have been avoided. Smokers who are 3.(care)cause about 200 deaths and over 6,000 fires. More than of those 4. die in fires are poisoned or harmed by smoke.If fire happens, do not attempt to fight the fire unless it is small. Try putting out a small fire with water. If 5. fire has spread or if the flames are more than 20 inches high, shut the door on it. Warn everyone else in the building and tell them to get out. You should leave and dial 911 for the fire department.Before 6.(go)into a room，check the door. If the handle or the door is hot, do not open it! Instead, put clothing or a wet towel at the bottom of it to keep smoke out. If the door is not hot, open it 7.(slow)．If there is a rush of smoke heat, close it again and shout to warn 8. (other)inside.Now open the window and shout “Fire!”. See whether you can drop safely to the ground. Use this 9.your escape course if you can. If you are not on ground level, break your fall by pushing a mat out first. Lower yourself at arm’s 10.(long) before dropping. Once outside, stay out outside and make sure the fire department is called.