In geometry, an ellipse may be defined

[Freeguy]

In geometry, an ellipse may be defined as the locus of all points ..... distances from two fixed points is constant.

1. which as the sum of
2. of the sum which
3. whose sum of whose
4. whose sum that the


I can't understand the structure of No.3. How can we use two whose or which, for example, together?

Thanks!

 

[Rover_KE]

Leaving your question aside for the moment, I can't make sense of any of those alternatives.

In future questions of this sort, please tell us what the answer key gave.

 

[alex_genius_20]

(I'm not a teacher)

Freeguy, to me, it makes no sense too. I googled it and found it. It's a Toefl test: Sample TOEFL Structure and Written Expression Questions

Rover, it's test number 13

 

[Freeguy]

Answer key: No.3

 

[Grumpy]

It would be better expressed as "...the locus of all points, the sum of whose distances from two fixed points is constant.

 

[Freeguy]

Can we use two whose together as a general rule?

 

[Grumpy]

I don't know if there's any specific rule forbidding it, but it's certainly something to be avoided if at all possible - as the foregoing comments by others make clear!