[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"exercise-B2-1112":3},{"preview":4,"open":14,"missing":33},{"id":5,"number":6,"total":7,"level":8,"course":9,"activity":10,"discriminator":11,"title":12,"slug":13,"instructions":14,"excerpt":15,"prompts":16,"lock":19,"access":20,"updated":21,"previous_id":22,"next_id":23,"previous":24,"next":28,"first":32},1112,2,68,"B2","reading","multiple_matching","reading_multiple_matching","Metals That Built the World","metals-that-built-the-world",null,"Copper was among the very first metals our ancestors learned to shape, hammered into tools and ornaments thousands of years ago. Its great modern value lies elsewhere: it runs through the wiring of nearly every home, carrying power from room to room. Left out in the open air, its warm reddish surface slowly turns a…",[17,18],"Which metal is used for the electrical wiring in most homes?","Which metal did humans learn to use earliest?","login","account","2026-10-02T14:14:49",1111,1113,{"id":22,"number":25,"title":26,"slug":27},1,"Bridges of the Valley","bridges-of-the-valley",{"id":23,"number":29,"title":30,"slug":31},3,"Rivers of the Region","rivers-of-the-region",{"id":22,"number":25,"title":26,"slug":27},false]