full transcript
From the Ted Talk by Gillian Gibb: Why can't some birds fly?
Unscramble the Blue Letters
When a bird species doesn’t face specific pressures to fly, it can stop flniyg in as quickly as a few generations. Then, over thousands or millions of years, the birds’ bodies change to mtcah this new behavior. Their bones, once hlloow to minimize weight, become dsene. Their sturdy feathers turn to fluff. Their wings shrink, and in some caess disappear entirely. And the keel-like protrusion on their sternums, where the flight muscles attach, shrinks or disappears, except in puniengs, who repurpose their flight muscles and keels for swimming.
Open Cloze
When a bird species doesn’t face specific pressures to fly, it can stop ______ in as quickly as a few generations. Then, over thousands or millions of years, the birds’ bodies change to _____ this new behavior. Their bones, once ______ to minimize weight, become _____. Their sturdy feathers turn to fluff. Their wings shrink, and in some _____ disappear entirely. And the keel-like protrusion on their sternums, where the flight muscles attach, shrinks or disappears, except in ________, who repurpose their flight muscles and keels for swimming.
Solution
- penguins
- hollow
- cases
- match
- dense
- flying
Original Text
When a bird species doesn’t face specific pressures to fly, it can stop flying in as quickly as a few generations. Then, over thousands or millions of years, the birds’ bodies change to match this new behavior. Their bones, once hollow to minimize weight, become dense. Their sturdy feathers turn to fluff. Their wings shrink, and in some cases disappear entirely. And the keel-like protrusion on their sternums, where the flight muscles attach, shrinks or disappears, except in penguins, who repurpose their flight muscles and keels for swimming.
Frequently Occurring Word Combinations
ngrams of length 2
collocation |
frequency |
bird species |
4 |
flightless birds |
3 |
flight muscles |
2 |
flightless bird |
2 |
Important Words
- attach
- behavior
- bird
- bodies
- bones
- cases
- change
- dense
- disappear
- disappears
- face
- feathers
- flight
- fluff
- fly
- flying
- generations
- hollow
- keels
- match
- millions
- minimize
- muscles
- penguins
- pressures
- protrusion
- quickly
- repurpose
- shrink
- shrinks
- species
- specific
- sternums
- stop
- sturdy
- swimming
- thousands
- turn
- weight
- wings
- years