Ancient cultures broke off pieces of obsidian to make knives and weapons such as arrows.

VOA: special.2009.09.16

Officials would order all lights in a city turned off to make it difficult for enemy planes to find a target in the dark of night.

VOA: special.2009.11.15

Captain Sullenberger walked through the plane twice to make sure everyone was off.

VOA: special.2009.01.30

Fraud,insecurity and the weather all threaten to make next month's run-off elections difficult for one of the world's newest democracies.

VOA: standard.2009.10.21

The FBI says the smugglers often threaten their victims and make it difficult for them to pay off their debts.

VOA: standard.2010.05.24

The president said both leaders will need to end delays and make sacrifices to revive the peace talks that broke off in 2008.

VOA: standard.2009.09.22

"It is a lot easier for firms to make the decision not to lay someone off than it is actually to decide to take someone on,"

VOA: standard.2009.11.06

But a few days ago, he told NBC television that he might not make an announcement until after the Afghan presidential run-off election scheduled for November 7.

VOA: standard.2009.10.26

make sense to people. It was like an alarmwent off in my head.

VOA: standard.other