The bell __ the end of the period rang, __our heated discussion.
A. indicating, interrupting B. indicated, interrupting
C. indicating, interrupted D. indicated, interrupted
_______cloning human embryos is not legal in many countries, some scientists are already pushing ahead with research in order to produce a cloned human baby.
A. While B. When C. Since D. if only
________ the programme, they have to stay there for another two weeks.
A Not completing B Not completed
C Not having completed D Having not completed
When the boss came in, these workers pretended to________ carefully.
A. working B. be working
C. work D. have been working
People often have this belief ___development is bad for the environment, but this does not have to be true.
A which B whose C that D when
The children were ______ for the accident. After all they were so young.
A. not to blame B. to not blame
C. not blamed D. to not be blamed
