1.   Although molecules consisting of rings of carbon and other atoms are common in nature and in the laboratory, the mechanical interlocking of neighboring rings seemed impossible until recently.

2.   But the pledges of support to Chirac make real campaigning virtually impossible until after the presidential elections.

3.   For the rich, it became impossible until the last few days to make international phone calls.

4.   The city agreed to include those guarantees in the legislation, but by then the Senate had adjourned, making official passage impossible until the Legislature convenes next month.

5.   The latter was preferable but universally considered impossible until Albright skillfully arranged the support that made the intervention international.

6.   Clashes with Argentina, France or Brazil would be impossible until the final.

7.   It is a long, expensive process but many Western officials claim reconciliation in Bosnia is impossible until all the missing have been found and the perpetrators face justice.

8.   It ultimately failed, with the Chinese government saying burial was impossible until reunification.

9.   President Chandrika Kumaratunga Friday warned that a military victory over Tamil rebels would be impossible until the government won the support of ethnic Tamils.