Answer:
There are too many options:
Tú lo estudias pero ellas no lo estudian.
Explanation:
Tú lo conoces pero ellas no lo conocen.
Tú lo meditas pero ellas no lo meditan.
Tú lo hiciste pero ellas no lo hicieron.
Since no doesn't indicate which verb to use, <u>you can use </u><u>some</u><u> verb</u> (in this case I used "do"). The verb must be conjugated in the preterite.
Look kid, this question has been up for 5 hours think its time to let it go......... hoped i helped. ✔verified✔