fill in the right tense

Tom Wilson 1) is (be) an explorer. He 2) ____________ be) to nearly every country in the world, but the most exciting time he 3) ________________ (ever/have) was when he 4) ________________ (go) to the Congo jungle. A magazine 5__________________ (ask) him to retrace the route of a famous explorer who 6) _________________ (disappear) in the 1920's. As he 7) ________________ follow) a small river he got separated from his guides. He 8) ________________ (go on) alone, hoping he 9) ____________________ (find) them, but instead he 10) ______________ (encounter) a group of natives. He 11) ____________ (stay) with them for several days and 12) ________________ (find out) that a very old woman 13) ___________________ actually/meet) the famous explorer. She 14) ___________________ (know) how he 15) __________________ die). Tom 16) ______________________ (become) very friendly with the natives and now he 17) ____________________ (plan) to go back and see them again. He is sure they 18) _________________________ (welcome) him back.