高中英语必修3 第29页 人民教育出版社的

1.What has not been discovered is his discovery.
2.Whether the other astronomers accept his ideas remains a question.
3.How life first appeared on earth is still a mystery to scientists.
4.Why the earth is becoming warmer is an important topic for research.
5.It amazed everybody that Stephen Hawking at 65 experienced zero gravity during a flight.
6.It is surprise that Pluto is no longer considered a planet in our solar system.