2014
高考英语阅读理解基础练习精品题（34）及答案阅读理解 bad teeth can be painful — and worse. they can even be deadly. infections (感染）of the gums (牙龈）and the teeth can cause bacteria (细菌）to go into the blood system. those bacteria can increase the chance of a heart attack and worsen the effects of other diseases. and adults are not the only ones at risk. for example, in 2007, doctors
