We should place emphasis on development and security, and develop nuclear energy on the base of security.
After _______ had happened he could not continue to work there.
She was so angry and spoke so fast that none of us understood _______ he said meant.
______ medicine works in a human body is a question _______ not everyone can understand fully.
____ has helped to save the drowning girl is worth praising.
I had neither a raincoat nor an umbrella. _______ I got wet through.