In the last two decades, space exploration___great contributions to weather forecasting.

C. Made

While mother________ dinner, the phone rang.

On July 20, 1969, Neil Armstrong ________ down onto the moon, the first person ever set foot on another planet.

She will go abroad as soon as she________ this English course.

We________ a party next week. Would you like to come?

The earth________ on the sun for its heat and light.

When boarding the plane, many passengers were annoyed because they ________ waiting in the airport for three and a half hours.

If coastal erosion continues to take place at the present rate, in another fifty years this beach________ any more.

I ________ my key. Can you help me look for it?

Fish________ on earth for ages.

The phone________ constantly since Jack won the first prize this morning.

They ________ this course by next June.

Alan took a photograph of Sandra while she________

D. Hadn’t looked

Last night Trista________ in bed when suddenly she heard a scream

B.Had read

I don’t feel good. I ________ home tomorrow.

By the end of this year, Tom ________English for three years.