11.   The Serbs have blocked the formation of a single central bank, failed to meet arms control limits and signed an economic and military cooperation agreement with Yugoslavia.

12.   The talks are aimed at resolving the guerrilla disarmament issue, which is blocking the formation of a new government in Northern Ireland.

13.   They insist that they will block the formation of a new government unless election irregularities are investigated.

14.   They start by noting, correctly, that cartilage contains a protein that blocks the formation of blood vessels.

15.   Tudjman lost municipal elections in Zagreb a year ago and has since blocked the formation of an opposition local council.

16.   Using laboratory animals, they showed the troponin I could block the formation of new blood vessels.

17.   We have identified new classes of inhibitors that block the formation of the abnormal prion protein.

18.   A high concentration of glucose acts like antifreeze in these frogs, blocking the formation of ice crystals in cells that would normally damage tissue.

19.   He has been quick to learn running and blocking formations and is always first to credit those around him.

20.   In all, a number of compounds that can block blood vessel formation have been discovered.