Подготовка к ЦТ. Tenses.

 Выберите подходящую форму глагола для каждого пропуска

In 1969, the first humans (1) ______ on the Moon. Since then, space exploration (2) ______ significantly. Currently, scientists (3) ______ on a mission to Mars. They believe that by the year 2040, the first colony (4) ______ there. However, many experts warn that if we (5) ______ to protect our own planet now, no other planet will save us in the future.

Варианты ответов:

1. 

a) landed

b) have landed

c) had landed

d) were landing

2.

a) advanced

b) has advanced

c) is advancing

d) had advanced

3.

a) work

b) are working

c) have worked

d) will work

4.

a) will build

b) will be built

c) will have been built

d) is built

5.

a) don't try

b) won't try

c) haven't tried

d) didn't try