Test 4 Section 1 Q5 GRE BigBook

Can someone please help me solve this using the math strategy. Thank you.

My Logic → Because is the support word here, the first part is -ve because of the word ‘difficult’

Difficult (-ve)------------------Because (+ve)------------------_______________(-ve)
for the second blank the ‘,’(comma) is the support word but I’m not able to get the answer (if this logic is correct)

Thank you

Remove the answer choices first.
Since we do not have any proof or clue for the first blank we will solve the second blank first.
“It combines concepts that should be kept ______”. We can apply the support/contrast here.
‘that’ signifies contrast here, so on the left we have ‘combines’ so the blank must be opposite of combines which is similar to separate. Hold your horses here, don’t jump to answers just yet.
Now we solve the first blank. as you said there is a support but support is from the first sentence to the second. ‘scientists have difficulty because …’ is the first idea and ‘in that’ signifies support so second idea which is ‘it combines concepts that should be kept (synonym of separate or separate)’
Now if it combines concepts that shouldn’t be combined how will the nomenclature be? It will be similar to not perfect or not cohesive or fitting together. So put that in the first blank.
Now we know what should be in the blanks let’s look at the answers.
Second blank is satisfied by both option D and option E since discrete also means to keep separate or not combined. For the first blank imprecise fits with what it should be but not descriptive. Hence we discard the option D and go with option E.