The radiation amount of a mobile phone for two half-hour periods per day is equal to _______ to an X-ray for ten seconds.
__________ is even more important is _________ the earth cooled down, water began to appear on its surface.
If you ______ smoke, please go outside.
His eyes stare _________ is left of the brother’s dinner on table.
He could not ________ Yong Hui ___________ telling people lies.
Sending a man into ____space is _________ complete success in the history of China.