Landing on Mars (Word formation)

Read the text and fill in the gaps with the correct form of the words in brackets.

Late Sunday evening, at the Jet Propulsion Laboratory in Pasadena, a group of scientists 1. (breathe) ………………… monitored the progress of a robotic explorer named Curiosity that was quickly descended toward the surface of Mars. When it landed 2. (safe) ……………. inside a crater on the Red Planet the scientists erupted with joy. It was 3. (just)……………. excitement.

Curiosity, in so many ways, represents the future of space 4. (explore) ……………….. for the United States and the world and, despite the 5. (perceive) …………………. that space travel and exploration is a dead or dying industry, Curiosity's landing indicates the exact opposite notion.

Over the next two years Curiosity will use its 6. (high) …………… sophisticated equipment to analyze Mars and attempt to determine whether or not life may have ever existed on our closest neighbor. It's all a part of an increased, 7. (nation) ……………… focused effort on exploring -  and 8. (event) …………………..  sending humans to - Mars. In fact, in 2010, President Obama made a promise in a speech at the Kennedy Space Center in Florida 8. (suggest)……………… that astronauts would reach Mars' orbit by the 2030s. That's just two decades away but there's no reason to believe that the goal is 9. (attain) ……………….  . After all, it's been more than four decades since astronauts walked on the moon and returned safely back to earth. And human space travel has little to show over that time period. (Greg Houle)

You will find the key in the first comment.