It will ___ us several years to learn a foreign language wel

B take
take + 时间 是固定用法,表示花了多久
It will take us several years to learn a foreign language well.
我们要花很多年才能学好一门外语
别的例句
It took me a week to finish the project.我花了一周才做好这个项目.
或者 It only takes a day to clean up the house.清洁房子只花一天就够了.
参考：英语牛人团
如果还有问题可以找我~

B
固定句型: It takes/took/will take sb. + 时间 + to do sth.