The result of the studies have had a strong impact on future developments.

must have been

had been

had to be

should have been

with

for

on

of

what’s the matter was

what was the matter

what the matter was

the matter was what

It was obvious that only a person with great talent could fake a painting so successfully

It was almost impossible for amateurs to realize that the painting was not authentic, though the experts could judge it quite easily

The painting looked so much like the authentic one that only the experts could tell it wasn’t genuine

It was hard for ordinary people to judge between the fake painting and the real one, but not for the experts

Mine is better than yours

My coffee is more good than yours

My coffee is better than your

My coffee is better than yours

not to cancel

their climb

extremely

Even though

wooden big round table

round big wooden table

big round wooden table

table big wooden round

do we

don't we

will we

shall we

The kidnappers threatened to kill our boy if we refused to pay the ransom

The kidnappers promised to kill our boy if we refused to pay the ransom

The kidnappers pledged to kill our boy if we did not pay the ransom

The kidnappers ordered to kill our boy if we did not pay the ransom

The mother was forced to keep her son’s mistake as a secret when he insisted

The boy requested his mother not to talk about his mistake any more

The boy begged his mother not to tell his father about his mistake

The boy earnestly insisted that his mother tell his father about his mistake