Originally from South America, the snails were accidentally introduced into the Ebro Delta by Global Aquatic Technologies, a company that raised the snails for fresh-water aquariums, but failed to prevent their escape.
2018年6月六級真題(第二套)閱讀 Section C
"This is the sweet spot between sharing and getting credit for it, while discouraging, " says Ivo Grigorov, a project coordinator at the National Institute of Aquatic Resources Research Secretariat in Charlottenlund, Denmark.