TENSES - 03

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

PUT THE VERBS IN THE CORRECT TENSE

1. Since Galileo (ANNOUNCE) that the earth rotates, over 300 years ago , astronomy (CHANGE) tremendously..
2. Astronomers (SPEND) several hours a day observing the stars, and their discoveries (GET) increasingly amazing.
3. Get away from that telescope! You (LOOK) through it for over 3 hours now.
4. He (SIT) in front of his monitor for 30 minutes when the fire (BREAK OUT) . The security guard (SLEEP) at the time.
5. I (NOT SEE) a comet for a long while. I think I (WATCH) the sky next weekend. If I (NOT SEE) anything, I (TRY) the new observatory which (JUST OPEN) down the road.
6. The satellite (BREAK DOWN) last month while scientists (OBSERVE) Saturn. They (NEVER HAVE) any problems with it before. NASA (LAUNCH) it in 1992. The repair crew (FIX) it a moment ago, and it (WORK) perfectly now, so they (NOT MISS) tomorrow’s eclipse.
7. COBE (ORBIT) the earth for years now, ever since it (REACH) its orbiting trajectory in October 1992.
8. They (WATCH) the constellation Canis Major for well over an hour when I finally (ARRIVE) at the observatory last night.
9. Neil Armstrong (DELIVER) a speech on CBS on 15th May 1994. He (NOT APPEAR) on TV for almost a year, not since April 93, when he (COMMEMORATE) the 25th anniversary of his Moon landing.