Which came first, the chicken or the egg? This is one of life’s ______ questions and people have been debating about it for thousands of years. Now scientists believe they have solved this ______. Researchers from Sheffield and Warwick Universities in England discovered the answer ____. They used a super computer to observe the shell-making process while a new shell was ____. Then they found one protein called OC17 that is ______ for forming eggshell. This is only found inside a chicken’s body, which is proof that the ______ came first. The team was ______ looking at how animals and birds make eggshells but suddenly made their surprising ______. The big question now is where chickens came from. The ______ is from dinosaurs.
The research team said eggshells are one of nature’s most ______ creations. Professor John Harding from the team told reporters: “Understanding how chickens make eggshells is fascinating in itself, but it can also be _____ in designing new materials.” Eggshells are very lightweight but incredibly strong. Even the most up-to-date materials _____ by the world’s top engineers cannot produce anything as ______ as an eggshell. Professor Harding added that ______ eggshells could help to cure bone diseases and design materials for the construction industry. “Nature has found wonderful ways that ___ for all kinds of problems in materials science and technology — we can learn a lot from them.” he said.

A．strangest B．best C．oldest D．Closest

A．puzzle B．fact C．history D．opinion

A．on purpose B．by chance C．without hesitation D．at work

A．breaking B．changing C．disappearing D．Forming

A．necessary B．easy C．kind D．impossible

A．egg B．eggshell C．chicken D．dinosaur

A．obviously B．originally C．thoughtfully D．surprisingly

A．invention B．mistake C．statement D．discovery

A．answer B．research C．road D．egg

A．common B．ridiculous C．funny D．amazing

A．interesting B．helpful C．normal D．correct

A．bought B．cut C．designed D．carried

A．brilliant B．ordinary C．1ight D．small

A．finding B．watching C．studying D．making

A．happen B．work C．wait D．Look