_______ changing the way we live can we save the earth．

Only if

If only

Just by

Only by

If we go there by taxi, It’s going to _______ very expensive．

leave out

work out

squeeze out

setout

If it _______ rain, the crops would be saved．

will

should

would

must

As is known to us all, wounds _______ to the air heal more quickly．

are exposed

is exposed

exposed

exposing

With enough evidence, he _______ with certainty that water carried the virus of cholera．

arranged

acquired

approved

announced

His failure at _________ first attempt didn’t disappoint him．Instead, he gathered his courage and tried ________ second time．

the; the

the; a

a ;the

a; a

With the price of oil _________, the economy of that country is slowing down．

rising up

going up

taking up

bringing up

Please remind me ________ he said he was going．I may be in time to see him off．

where

when

how

what

If you _________ any problems when you arrive at the airport, give me a ring．

come up with

set about

run into

put aside

You _________ to leave until you _________ your work．

won’t be allowed; have finished

won’t allow; finish

won’t be allowed; will finish

won’t allow; will finish