Writing
Unit 4 Astronomy:
the science of the stars
词汇训练
research 2. explore1) 2)
serious study of a subject， in order to discover new facts or test new ideas
to travel around an area in order to find out about it
to look at， to discuss or think about something carefully
词汇训练
3. launch1) 2) 4. land1) 2)
to start something， usually something big or important
to make a plane move safely down onto the ground at the end of a journey
to arrive somewhere in a plane， boat etc.
to send a weapon or spac ...