Many schools used K12 online application during Covid-19 pandemic.

A. Application was used K12 online by many schools during Covid-19 pandemic.

B. K12 online application was used by many schools during Covid-19 pandemic.

C. Application is used K12 online by many schools during Covid-19 pandemic.

D. K12 online application is used by many schools during Covid-19 pandemic.

Ôn thi vào 10 (Viết lại câu)