1.   Also reaching the market this year are soybeans engineered to be resistant to common herbicides so that farmers have more flexibility in how they use weedkillers.

2.   It is a common herbicide, used by millions of homeowners trying to control weeds in their lawns.

3.   That raises the threat of superweeds impervious to common herbicides.

4.   The most common herbicide was Agent Orange, named for the orange band around its containers.