Recent analyses of ice cores show that carbon dioxide levels were ________ lower
over the last 600,000 years than they are now.
The problem of global warming is ________ as one of the most serious environmental
problems of our time.
Not only ________ this planet, but we have completely wiped out hundreds of
do we pollute
The last Pied Raven was shot in the late 1940s. The species ________ saved but
people were too ignorant.
can have been
could have been
were able to be
The only way to stop overpopulation is to reduce the birth rate. This ________ a
question of whether people have a right to have children.
If you want to save money and the environment, try ________ less detergent, shampoo
and other cleaning materials.
It's by sorting and recycling our garbage ________ we can save the planet.
Fortunately, ________ no longer on the list of endangered species.
a bald eagle is
bald eagle is
bald eagles are
the bald eagle is
Mike and Debbie used to be good friends but they fell ________ over the issue of
climate change. Mike believes it's just a scam, a tool being used to make
certain individuals rich.
The idea of using public transport instead of driving is nice but it's not
what most people are willing to put ________.
on up with a daily basis
on with a daily basis
up on a daily basis with
up with on a daily basis
According to S. Edwards, a million species ________ by 2050.
are going to disappear
will be disappearing
will have been disappearing
will have disappeared
Despite everything we hear from TV and the radio, people ________ to destroy the
seem unable to avoid
According to research, forests are dying twice ________ they did 20 years ago
because of climate change.
as fast as
as fast than
more fast as
If you'd seen Al Gore's movie “An Inconvenient Truth”, you ________ a lot
differently about the issue of global warming.
would have felt
I had ________ success with my conservation project in my company. It was dismissed
as being too costly.