Choose the correct option a, b, c or d to complete this passage.

The electronic computer is the most (1).......... invention since steam engine. While the industrial revolution (2) ..........changed the nature of (3) .......... work, the computer revolution is now changing the work (4) .......... by the brain. Nowadays micro-computers are (5) .......... in hundreds of thousands and are constantly (6) .......... equipped with more and more ingenious (7) .......... Contrary to popular belief, computers (8) ..........  cannot make mistakes. The answer will always be correct (9) .......... the programmed fed (10) .......... the computer is correct.

(1) ...................

• A. 
  powerful
• B. 
  significant
• C. 
  strange
• D. 
  mysterious