Sentence Correction

Art historians are using a process known as infrared scanning in analyzing the Mona Lisa to determine if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done by many artists of the time.

A. if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done

B. if it had been altered since completion and if Leonardo da Vinci first sketched the figure in black, a practice employed

C. whether it has been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice employed

D. whether it was altered since completion and whether Leonardo da Vinci first sketched the figure in black, as was done

E. whether it had been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice done

hope this helps

daretodream wrote:
Art historians are using a process known as infrared scanning in analyzing the Mona Lisa to determine if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done by many artists of the time.

A. if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done - if is incorrect coz if is used for hypothetical sentences.ELIMINATE

B. if it had been altered since completion and if Leonardo da Vinci first sketched the figure in black, a practice employed - if is incorrect coz if is used for hypothetical sentences.ELIMINATE

C. whether it has been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice employed - whether correctly used. has been correctly used. practice employed correctly used. CORRECT

D. whether it was altered since completion and whether Leonardo da Vinci first sketched the figure in black, as was done - the process is used in present. past tense is wrong here. ELIMINATE

E. whether it had been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice done
- a practice is not done. its employed. Also had been is not required here. ELIMINATE

C is correct for one more reason that is when since is used the tense should be present perfect and not past perfect or past tense.

Hope this helps

IMO,
C is the correct answer.
A,B --out "whether" is appropriate in this sentence

C --> present perfect is required in the first part (Scanning is using to find anyone altered..pciture.. till today..). Second part past tense is required (because sketch is done in the past)


D --> first part.. present perfect tense is required.
E --> past perect is illogical here.

daretodream wrote:Art historians are using a process known as infrared scanning in analyzing the Mona Lisa to determine if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done by many artists of the time.

A. if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black, as done

B. if it had been altered since completion and if Leonardo da Vinci first sketched the figure in black, a practice employed

C. whether it has been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice employed

D. whether it was altered since completion and whether Leonardo da Vinci first sketched the figure in black, as was done

E. whether it had been altered since completion and whether Leonardo da Vinci first sketched the figure in black, a practice done

C - since ---- implies from past till present (now) - so, "has been" is correct

A, B - incorrect - use of "if" -

D - incorrect - wrong tense was - must be present tense.

E - incorrect - past perfect (wrong tense) -- illogically suggests alteration was done before the completion of painting

komal wrote:
C - since ---- implies from past till present (now) - so, "has been" is correct

Is there some rule when u can use present perfect ? like which other words besides 'since' ?
Any such rule for any other tenses ?