Complete the second sentence so that it has the same meaning to the first one. Ose the word in brackets.
1. What are your plans for the weekend? (do) =>What
2. Peter knew how to skate when he was 12. (could)
=> Peter
3. The last time they visited Europe was two years ago. (not)
=>They
4. Robots are not as intelligent as humans. (than)
=> Humans
5. How long have you learned English? (start)
=>When