Since you got ________ wrong answer, you should do it for ________ second time．

a; a

the; the

a; the

the; /

The murderer was brought in, with his hands ________ behind his back．

tying

having tied

to be tied

tied

The earth ________ to be flat．

was used to be thought

used to be thought

was used to think

used to think

She always says the heavy traffic often makes her being late, but ________, it is because she often gets up late．

actually

exactly

indeed

optimally

Recently accidents happened to coal mines have been ________．

often

usual

frequent

common

The scientist has checked up the result many times．________, it can’t be wrong．

Therefore

More or less

However

Sooner or later

The president declared that he would ________ what he had said, that’s to say, the country would not withdraw their troops in Afganastan．

break out

keep out

watch out

back out

CO₂ differs ________ both physical and chemical qualities ________ CO．

from; in

in; from

from; from

in; in

The ________ of America changed the world a lot．

discovery

invention

uncovery

recovery

His carelessness brought us much trouble, so he must ________ us all．

thank

forgive

thankful

apologise to