Zerogravitylookscool．Butwhataboutthethingnoonelikestotalkabout？Yes，thatisright：goingtobathroom．Zerogravitymakesthiseverydaytaskquiteachallenge．Astronautshavetobetoilet-trainedalloveragain．TheApolloastro

Question

Zero gravity looks cool．But what about the thing no one likes to talk about？Yes，that is right：going to bathroom．Zero gravity makes this everyday task quite a challenge．Astronauts have to be toilet-trained all over again．
The Apollo astronauts raised themselves off the seat of their chairs and stuck a clear plastic bag to their back sides with sticky strips．A second astronaut watched closely to be sure no waste matter escaped the seal．（You would not want that stuff floating around the cabin!） When the deed was done，the astronaut cleaned up with a piece of plastic attached to the inside of the bag，removed the bag，dropped a disinfectant pill in with the waste matter，and put the whole thing，sealed，into a special container．
Donald W．Rethke，an engineer for Hamilton Standard Space Systems，developed a more private way to answer nature's call：the space toilet．It is somewhat like the kind of toilet one would find on commercial airplanes---with unique adaptations for zero gravity，of course．For instance，it has thigh bars that keep the astronaut from floating off the seat．
The astronaut （male or female） defecates （排便） in a bag and urinates （排尿） in a hose．Solid and liquid wastes are kept separated because at least 85% of the urine is recycled and，yes，after careful filtration，used for drinking and other purposes．（Water is always in demand in space．） A vacuum sucks the waste materials into the toilet，where the waste is compacted into hamburger-like patties for easy storage．Although not exactly like an earthbound visit to the toilet，it is at the very least much more private than in the early days of space travel．

28．According to the first paragraph，the lack of the gravity can turn something as simple as___into a major challenge．
A．eating        B．taking baths       C．sleeping        D．answering nature's call
29．How did astronauts use toilet systems in the Apollo days？
   A．None of the waste was separated as it is now．
   B．Solid waste was compressed and stored on board．
   C．The toilet units used water to remove the waste through the system．
   D．The astronauts each used their own private restroom．
30．To ensure the user remains seated，the toilet comes equipped with___
   A．a plastic bag      B．a sticky strip   C．a wide hose       D．a thigh bar
31．What can be inferred from the fact that most of the astronauts'urine is recycled？___
   A．The recycled water tastes better．
   B．Water is limited on the space shuttle．
   C．It is very convenient to get their urine recycled．
   D．Space science includes recycling urine．

Answer 1

答案：DADB
28．D；判断推理题，根据第一段中的Yes，that is right：going to bathroom．Zero gravity makes this everyday task quite a challenge．得知宇航员在太空上厕所是一件很困难的事情；结合第三段中的Donald W．Rethke，an engineer for Hamilton Standard Space Systems，developed a more private way to answer nature's call：the space toilet．得知W．Rethke把上厕所当成answer nature's call，故选项D正确．
29．A；判断推理题，根据第四段 astronaut （male or female） defecates （排便） in a bag and urinates （排尿） in a hose．Solid and liquid wastes are kept separated because at least 85% of the urine is recycled and，yes，after careful filtration，used for drinking and other purposes．可知宇航员的粪便的处理方式是不一样的，故答案选A．
30．D； 细节理解题，第三段最后一句For instance，it has thigh bars that keep the astronaut from floating off the seat．可知为了让宇航员坐在座位上，使用了thigh bars 来固定宇航员，故答案D正确．
31．B；判断推理题，根据文中的Solid and liquid wastes are kept separated because at least 85% of the urine is recycled and，yes，after careful filtration，used for drinking and other purposes．（Water is always in demand in space．）可以判定选项B正确．