Can someone explain why A is wrong and how D is correct?
Hi
globaldesi,
Persistence of vision, the condition when your eyes bridge the gaps of darkness between flashes of light, explains the seeming magic produced by the stroboscope, an instrument that appears to freeze the swiftest motions while they are still going on.
'Persistence of vision' means 'the continued or prolonged existence of vision', and it is not a condition but a phenomenon.
a) the condition when your eyes bridge - When is used to refer time/at the time (When the new park opens, I’ll go there every day.)
b) when your eyes bridge - same as A
c) the condition of your eyes bridging - Meaning error - 'Persistence of vision' is not the condition of eyes and 'bridging' is illogically modifying eyes
d) which occurs when your eyes bridge - which is correctly modifying 'persistence
of vision' and 'when' is correctly modifying the time 'when Persistence of vision occurs'
e) occurring when your eyes bridge - ',' (comma) + verbing modifier incorrectly modifying a noun
hope it helps.