[Grammar] Error Identification

[ocean_soul]

There may be a mistake in A,B or C or no mistake at all:

1.In A.medieval Europe it was B.a crime to sell goods for a higher price than you paid for them unless you C.had increased their value.
2. A.New research on the ecology of the Scottish loch B.strongly suggests that Loch Ness C.could not support a huge, long-necked, prehistoric sea monster.
3.It is easy to feel distressed about the world: A.a billion people are still poor, the earth’s population B.is doubled, C.the environment is being damaged, governments are corrupt.
4.The Central American country Panama A.has linked B.to US interests ever since settlers bound for California C.crossed the country back in the 19th century.
5.Some researchers A.are thinking that mountain ranges may cause large climatic upheavals B.by changing patterns in C.the upper atmosphere.
6.A.Two aircrafts narrowly missed B.colliding with a foreign airliner, but both of these incidents appear C.to have been hushed up.
7.Almost A.half the world’s population now lives in cities and it’s estimated that by 2025 this proportion will B.rise to C.two-third of the world’s population.
8.A.While Jim seems B.to have succeeded in blocking out the past, Hill has never attempted C.to hide the influence of his father’s memory on his career.
9.A.Flames B.have been spotted from the lake shore late at night while the mansion’s owners were away from the island C.for dinner.
10.Seats A.are selling B.fast so don’t risk C.to miss out the holiday of your dreams by booking too late, was the tourist agent’s advice.
11.More than A.a thousand police B.has been called in to ensure that the event goes according C.to plan.
12.I A.have been waving my arms for ages but I couldn’t attract the waiter, so I used my mobile phone to ring up the restaurant B.from the table and ask C.for more coffee.
13.A Chinese folk tale A.tells about a frog that B.lived all its life in a well and when one day it hopped out it was astonished C.to find what a limited view of the world it had always had.
14.The professor’s example related A.to metaphors and the danger they conceal was, ‘The phrase “nuclear umbrella” might lead people B.to assume that nuclear devices are C.safety equipments.’
15.The most important building blocks of the brain A.are the nerve cells, or neurons, B.which transmit information C.in the form of electrical impulses.
16.The young actor A.did one interview with the film director, and he was so intelligent, so able B.to move comically that the director knew he C.had to have him.

My answers:1-no error
2.-no error
3.A-a billion people
4.A-has been linked
5.A-think
6.no error
7.no error
8.no error
9.B.-were spotted
10.A-are being sold
11.A.thousand policemen
12.A.-waved
13.C-to find out
14.B-the assumption
15.no error
16.no error

[Anglika]

7 - C two-thirds [If you divide something into three equal sections there are three thirds]

10 B missing

11 B have been [police is accepted as a contraction for policemen, but you could change it]

12 A had been

13 no error

14 C equipment [singular]

[ocean_soul]

Thanks for the fast answer,Anglika!Are the others right? Oh and I wanted to ask: I have this sentence-I think they will accept the proposal if the sum needed for the purpose is not too big.
How should I do it using 'unless'?
1.I think they will accept the proposal unless the sum needed for the purpose is not too big.
2.I think they will accept the proposal unless the sum needed for the purpose is too big.

[Anglika]

Originally Posted by ocean_soul

Thanks for the fast answer,Anglika!Are the others right? Oh and I wanted to ask: I have this sentence-I think they will accept the proposal if the sum needed for the purpose is not too big.
How should I do it using 'unless'?
1.I think they will accept the proposal unless the sum needed for the purpose is not too big.
2.I think they will accept the proposal unless the sum needed for the purpose is too big.

The others look right to me.

#2 is the right alternative using "unless" if you want to say that too much money is going to be needed.

[Barb_D]

#6, at least in the US: Aircraft.

[Anglika]

Ha! Missed that