빈칸에 알맞은 것을 고르시오.

He __________ ethics from 2018.

• was studying

• has been studying

빈칸에 알맞은 것을 고르시오.

They __________ dessert since 6 o’clock.

• has been making

• were making

빈칸에 알맞은 것을 고르시오.

He __________ in his room at midnight last night.

• was sleep

• was sleeping

빈칸에 알맞은 것을 고르시오.

They __________ to understand the rule for two hours.

• have been tried

• have been trying

빈칸에 알맞은 것을 고르시오.

Betty __________ with her friends since this evening.

• has been chatting

• has chatting

빈칸에 알맞은 것을 고르시오.

I __________ this video clip since 1 P. M.

• was watching

• have been watching

빈칸에 알맞은 것을 고르시오.

They __________ the Christmas tree when I came back home.

• was decorate

• were decorating

빈칸에 알맞은 것을 고르시오.

Chris __________ in the line from early morning.

• has been standing

• has been stood

빈칸에 알맞은 것을 고르시오.

She __________ about the tricky question for 20 minutes.

• has thinking

• has been thinking

빈칸에 알맞은 것을 고르시오.

We __________ for you since 12 o’clock

• have been waiting

• have been waited