It was the largest and most difficult structure of its kind ever built when work started in nineteen thirty-one.

VOA: special.2009.08.12

Its creators said it is the longest chemically designed DNA structure ever produced in a laboratory.

VOA: special.2010.07.20

Each kind of mineral has its own structure and chemicals.

VOA: special.2009.11.17

The Lisbon Treaty is set to tighten the existing structure of the European Union to strengthen its leadership and international clout.

VOA: standard.2009.10.02

It has its own structure and set of rules that apply in it."

VOA: standard.2010.07.16