Ex. F page 107 - Choose the correct option.

Many explorers have ........ to the North Pole.

• a. go

• b. been

• c. going

Nobody is here. They have ...... to find new species in the rainforest.

• a. gone

• b. been

• c. going

Edmund Hillary and Tenzing Norgay got to the top of Mount Everest ...... .

• a. since 1953

• b. over 60 years ago

• c. for almost 60 years.

Kate has been studying endangered species ....... .

• a. for ten years

• b. since ten years

• c. ten years

He has been collecting fossils ...... he was a student.

• a. for

• b. ago

• c. since