Here are the sentences with the correct words circled:
0. When we arrive/ I 'll arrive, we send/ I'll send you a text message. 1. He 'll look /look for the book as soon as he 's/ 'll be home. 2. We watch/ 'll watch the film as soon as the electricity comes/ will come back on. 3. As soon get/ 'll get the money, I pay/ I'll pay you back. 4. I take/'ll take you to the new museum when