【challenge】v. to invite someone to compete or take part, especially in a game or argument
Tina has challenged me to a game of poker.
【dense】adj.having parts that are close together so that it is difficult to go or see through
The plane crashed in heavy rain and dense fog.
【plow】v.to dig into the earth with a large farming tool to make the earth ready for planting
It rained so much I thought I’d have to plow the crops under