Such a narrow focus can ------ to problems.
trigger
lead
result
cause
The sites ---------- from single hamlets to large villages.
graded
lined
ranged
covered
----- the absence of predators, birds can be trained to call for help.
In
Birds listen to the alarm calls of other species ,---------- it possible for them to take advantage.
making
The discoveries have added ---------- to the idea the population of the Amazon were much greater than once thought.
size
weight
charge
force
Deforestation has helped reveal evidence, mainly in the ---------- of earthworks.
Form
Model
Feature
Pattern
An obsession with achieving goals is a common--------- of life in many parts of the world.
point
character
feature
matter
Birds can learn unfamiliar calls,----------- the bird that made that call even being visible.
without
The research team also came --------- fragments of ceramics.
across
over
through
about
In one recent study in a ---------- remote region of the Amazon,....
roughly
virtually
practically
relatively
Birds learn life skills in various ways. .....some of what they know is innate, some is acquired.
While
It is believed European diseases arrived in the area ,even before Europeans ever ------- foot in the area.
put
left
set
stepped
These accounts were subsequently --------------- as fantasies.
Dismissed
Denied
Dispelled
Declined
This is a useful skill, given ----- hard it can be to see predators.
how
There are many eyes looking out ------- danger.
for
People are encouraged to ------- goals and then strive to achieve them.
set
lay
fit
mark
Researchers --------- satellite images and identified 81 ancient sites.
peered
scoured
sought
probed
Individual birds learn from each other --------- than through direct experience.
Rather
Wrens didn't flee from unfamiliar sounds. But after training, they usually---------- so.
did
The first Europeans to travel to the Amazon region ------------ seeing widespread settlements.
notified
announced
reported
informed