Hi, answers are sea wall, groin, breakwater.
I think it is difficult to control pig weed include; The number of inches it grows daily; its thick, woody stem and also the number of seeds it produces.
The pigweeds are an annual plant that germinates by release of their seeds starting in late winter until summer.
They are connected in the foodweb
One is to involve exercising curiosity in order to ask questions and seek answers about the universe.