Almostallofushavebeenthere：Asenseofuneasinessstrikesuswhenweseethebatteryrunninglowonthesmartphone．Whiletoday'ssmartphonesenableustosurftheInternet，takepicturesandplaymusic，theirlimited，sometimesannoyingly
Almost all of us have been there：A sense of uneasiness strikes us when we see the battery running low on the smartphone．While today's smartphones enable us to surf the Internet，take pictures and play music，their limited，sometimes annoyingly short battery life has started to make people full of memories of early models．"My favorite phone of all time was a silver Nokia 6310i from the early 2000s．It may be primitive by today's standards，but it could run for 17days on a single charge，"wrote Daily Mail columnist David Derbyshire．
But scientists spend no time thinking about the past．They have built an aluminium （铝） battery which could be a cheap，fast-charging alternative to current designs．
You can squeeze，and practically bend it in half without breaking the packet．It is more environmentally friendly than alkaline （碱性的） batteries，and more safe than lithium （锂） batteries-it won't catch fire"even if you drill through it"，as Hongjie Dai of Stanford University told The Telegraph．The battery is the work of a team led by Dai．And the best part is that it has a recharge time of around one minute．
However，at present，the only problem is that it produces just half the voltage （电压） of a typical lithium battery．But Dai explained they were setting about changing the voltage and energy density（密度）"．"Our battery has everything else you'd dream that a battery should have．I see this as a new battery in its early days，"he told The Telegraph．
72．How many advantages does the aluminium battery have according to the article？___
A.2
B.3
C.4
D.5
73．The passage suggests that___．
A．the aluminium battery catches fire easily if drilled
B．the aluminium battery still needs improving before it can be widely used
C．the aluminium battery is larger in size than alkaline batteries
D．scientists find it a real challenge to change the voltage of the alumin