3道语法题

题目

3道语法题
1.Among the Inuit peoples of arctic Canada,poetry contests are held to settle conflicts that might otherwise "be" disruptive to families and communities.
文中的"be"是正确的.为什么引号处可以用be?
2.In 1508,the Spanish explorer Juan Ponce de Leon -- the same Ponce de Leon who later "would seek" the fountain of youth -- landed on Pueto Rico accompanied by a small force
文中“would seek”是正确的.为什么这里可以用“would"?
3.Malaria,a disease which "has been" almost completely eradicated in the US,is still a threat to travelers in some foreign countries.
文中”has been"是正确的.为什么这里可以用完成时?一般现在时不行么?
第一题就免了吧...亏我还打字上去的，没看到"might"...请教后面两题

答案

第一个应该是词组 might be 第二个who later "would seek" the fountain of youth 是过去将来时 第三个almost completely eradicated in the US是过去发生的对现在造成影响,用完成时