10．It is a tall tale that terrifies most young children．Swallow a piece of chewing gum and it will remain in your body for seven years before it is digested．Or so they say．An even worse tale is that swallowed gum can wrap itself around your heart．
But what does happen if you should accidentally eat a stick of gum？Chewing gum is made out of gum base，sweeteners，coloring and flavoring．The gum base is pretty indigestible-it is a mixture of different ingredients（成分）that our body can't use．
Most of the time，your stomach really cannot break down the gum the way it would break down other foods．However，your digestive system has another way to deal with things you swallow．After all，we eat lots of things that we are unable to fully digest．They keep moving along until they make it all the way through the gut（肠子）and come out at the other end one to two days later．
The saliva（唾液）in our mouths will make an attempt at digesting chewing gum as soon as we put it in our mouths．It might get through the shell but many of gum's base ingredients are indigestible．It's then down to our stomach muscles-which contract and relax，much like the way an earthworm moves-to slowly force the things that we swallow through our systems．
Swallowing a huge piece of gum or swallowing many small pieces of gum in a short time can cause a blockage within the digestive system，most often in children，who have a thinner digestive tube than adults-but this is extremely rare．
68．A child might feel terrified after swallowing chewing gum mainly becauseA．
A．they believe the tall tales about chewing gum
B．chewing gum will stay in their body for many years
C．their heart will be wrapped by chewing gum
D．chewing gum is indigestible for children
69．What happens to the food that can't be fully broken down？B．
A．It remains in our digestive system forever
B．It will be eventually moved out of our body
C．It will fight against the power of the gut
D．It will stick to the gut for one or two days
70．The word It （in the 4th paragraph） refers to"B"．
A．the attempt B．the salvia C．the shell D．the gum base
71．What would be the best title for text？C
A．How does our digestive system work？
B．Can chewing gum be swallowed by kids？
C．Does swallowing chewing gum matter？
D．Why swallowing chewing gum frightens kids？
分析 本文属于说明文阅读，作者向我们介绍了人们传言吞食的口香糖要花七八年才能被消化，甚至还有传言说口香糖会在你的肚子里缠绕．然而，真相是对于那些不能被人体消化的食物，消化系统会将它们排出体外．
解答 68．A 推理判断题．根据文章第一段It is a tall tale that terrifies most young children．和An even worse tale is that swallowed gum can wrap itself around your heart．可知孩子们因为听了许多关于口香糖的故事，所以会对吞食口香糖感到恐惧，故选A．
69．B 细节理解题．根据第三段They keep moving along until they make it all the way through the gut and come out at the other end one or two days later．可知那些不能被消化的食物最后会被排除体外，故选B．
70．B 词义猜测题，根据第四段The saliva（唾液）in our mouths will make an attempt at digesting chewing gum as soon as we put it in our mouths．It might get through the shell but many of gum's base ingredients are indigestible．可知文章中的"It"指的是口中的唾液，它会帮助我们消化食物中的一些成分，故选B．
71．C 主旨大意题，通读全文可知，本文主要针对吞食口香糖是否有危害这个问题向我们进行了解释，澄清了口香糖会在人体内缠绕的谣言，故选C．
点评 考查学生的细节理解和推理判断能力．做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确选择．在做推理判断题时不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
