I USUALLY GO TO BED ...MIDNIGHT...SATURDAY.A. ON/ON B. ON/AT C.AT/O...

4. - DE KIEM TRA TA 7 LAN 1
DE KIEM TRA TA 7 LAN 1

4. I usually go to bed ...midnight...Saturday.

A. on/on

B. on/at

C.at/on

D. at/ by