用适当的句子、短语或单词完成对话，使对话完整正确。

Daming: Hi, Tony. What are you up to?

Tony: Hi, Daming. I’ve just made a model spaceship for our school project.

Daming: I’m not sure how to make it. _______21_______?

Tony: Sure, no problem. Have you heard the news? Scientists have sent a spaceship to Mars.

Daming: _______22_______ yet?

Tony: Yes, it has arrived already. That’s why it’s on the news.

Daming: Are there any astronauts in the spaceship?

Tony: _______23_______.

Daming: Why not? Astronauts have already been to the moon.

Tony: Yes, but no one has been to Mars yet. Lots of scientists are working hard in order to send astronauts to Mars one day.

Daming: That’s interesting! _______24_______ information on space travel?

Tony: You can go online to search for information.

Daming: I will. _______25_______, Tony.