Choose the correct answers.

1 Marc and Craig (have done /have been) doing volunteer work for over two decades now.
2 They came up with the idea to start Me to We while they (built / were building) a school in Ecuador.
3 In 2012, the Me to We organization (helped / was helping) to plant 195,000 trees.
4 So far, between them, they (have published / have been publishing) eleven books about their charitable work.
5 They both regularly (contribute / are contributing) to numerous newspapers and magazines.
6 In their newspaper column Ask the Kielburgers, they (offer / are offering) tips on ways to give back to the world.
7 Currently, the brothers (prepare/are preparing) their next annual We Day event.
8 Since 1995, 278,000 people (have attended / have been attending) a We Day event.​