下列各句的A、B、C、D中有一处错误，请在不改变句子意思的前提下，将正确答案写在题后的横线上。
1. Please tell him don't to be late for school. 1. _______
A B C D
2. Kitty's uncle has gone to Beijing twice. 2. _______
A B C D
3. We don't know what to solve these problems. 3. _______
A B C D
4. It's very nice for you to bring me the newspapers and magazines. 4. _______
A B C D
5. The scientists are wondering whether can people grow plants on Mars. 5. _______
A B C D