These materials help keep the water in correct balance with the soil.

VOA: special.2009.01.12

These contracts let buyers lock in a price for basic materials.

VOA: special.2010.12.03

These tapestries are made of the materials silk and wool.

VOA: special.2010.02.03

"We will set new standards, expand our cooperation with Russia, and pursue new partnerships to lock down these sensitive materials."

VOA: standard.2010.04.06

"What we expect to see come out of the summit is a communiqu with an action plan, a specific timeline with very particular benchmarks that are measurable on how to secure and lockdown these vulnerable nuclear materials."

VOA: standard.2010.04.06