—Don't worry. I (bring) it back already.
space travel, have been to, work hard, a group of, by spaceship
David already a book.
finished homework?
Peter a model spaceship?
Yes, .
He worked late into the night the task.
Scientists life on other planets.
The teacher told us that the moon the earth.
for anyone get in because the door is locked.
—当然可以,没问题。
—Could you help me do some dishes?
—Sure, .
—我在给我的朋友发一封电子邮件。
—What are you ?
—I'man emailmy friend.
Yesterday morning, I saw my teacher .