A test for an insecticide found 20 mg of the chemical in a 500 mL sample of pond water. What is the concentration of the insecticide in ppm?

the correct answer is d.   to change the pace

explanation:

write it down

then read over it

then trun it in

ls there any answer choices if there is then l can try to you

in the following paragraph, the fourth sentence the correct answer is: three personal subject pronouns

”she was embarrassed when she found that they had been put back on the shelves…”

a   subject pronoun is a personal pronoun. i, you, he, she it, we, they.  

in the sentence it can be observed she, used twice and they used once. is for this reason that is a three personal subject pronoun sentence.