1. The American space agency has drawn up a shortlist of ten research projects that will form the basis of an program to explore the planet Mars next year. (ambition)

2. As the saying goes, " we stand, divided we fall."(union)

3. Eugene O'Neill wrote more than 35 plays and was the first American awarded a Nobel Prize for Literature. (drama)

4. I am retired and now working as a in an organization helping orphans. (voluntary)

5. Compared to some other developing countries, the cell phone market in China is . (flourish)