Choose the best answer: Opera singer Maria Callas was known for her ... and power voice

Choose the best answer:
1. Opera singer Maria Callas was known for her .......... and power voice.
A. intensity          B. intensify          C. intense          D. intensely
2. The student didn't do well in the class. He had a problem with ..........
A. absent              B. absently         C. absence        D. absenteeism
3. The sick child must stay away from others because he has a .......... disease.
A. communicate   B. communicable  C. communicator  D. communication
4. I don't understand what these results ..........
A. significant          B. signify              C. significance   D. significantly
5. Their failure to act is .......... of their lack of interest.
A. indicate             B. indicator           C. indication      D. indicative
6. "Since the goal seems .........., I believe we should begin at once." Tom argued.
A. achievements     B. achieve          C. achievable     D. achieving