VOA 《US Farmers Look For Policy Clues in Biden Cabinet Picks》
After tumultuous four years marked by trade uncertainty and now a global pandemic, many farmers acorss the country still
supported President Donald Trump.
上句marked by这里的mark究竟是什么意思呢?另外,顺便请教老师为什么tumultuous在four前,而不是four tumultuous years ?