Since the implementation of stricter clean air controls over

Question

Since the implementation of stricter clean air controls over the past twenty years, some of the worst air pollution from old factories caused by sulfur oxides have been almost completely eliminated.

A) from old factories caused by sulfur oxides have been almost completely eliminated. 
B) caused by sulfur oxides from old factories have been almost completely eliminated. 
C) caused by sulfur oxides from old factories has been almost completely eliminated. 
D) from old factories caused by sulfur oxides will be almost completely eliminated. 
E) from old factories caused by sulfur oxides is to be almost completely eliminated.

OA IS C

some of the worst air pollution should be modified by have??? why has?

GyanOne · Answer

'Pollution' is an uncountable noun. An uncountable noun is always treated as one unit. Some other examples include water, food, money, and music.

himadeepm · Answer

Pollution can't be measured in terms of numbers.It can be measured only in terms of amount, which is always singular

Pritishd · Answer

A) from old factories caused by sulfur oxides have been almost completely eliminated 
The subject of the underlined clause sentence is pollution which is singular and hence in order to maintain subject-verb agreement we need the singular verb 'has' and not 'have'. We can eliminated on the basis of this rule
 B) caused by sulfur oxides from old factories have been almost completely eliminated 
Same as B
 C) caused by sulfur oxides from old factories has been almost completely eliminated 
The original sentence says that the control implemented over the past 20 years have over the years has considerably reduced pollution. Hence the action started in the past and continues in the present and that's why we need present perfect tense 'has been eliminated'
 D) from old factories caused by sulfur oxides will be almost completely eliminated 
This option has two issues i) It does not use present perfect tense and ii) 'Will' indicates certainty (100%) and from a meaning point of view, combining with almost makes it incorrect 
 E) from old factories caused by sulfur oxides is to be almost completely eliminated 
This option can be eliminated for not using the present perfect tense

Ans.  C

P.S  kapilagrawal123  - Request you to show the underlined part in your post

Since the implementation of stricter clean air controls over

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Since the implementation of stricter clean air controls over

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