Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 3 to 7.

The trend for children to multitask by juggling all sorts of electronic gadgets at the same time is (3) _____ damaging their levels of concentration, scientists have warned. Rocketing use of the Internet, iPods, mobile phones, and DVDs lies behind that finding. Scientists have confirmed the belief of many parents that it is impossible to concentrate on more than one thing at the same time. They found that children (4) _____ homework while sending messages via the Internet can end up spending 50% longer than if they had done each task separately.
David E Meyer, (5) _____ is the Professor of Cognitive Psychology at the University of Michigan, said that true multitasking is only possible for simple activities such as ironing and listening to the radio. He ran experiments demonstrating that young adults who had to switch from one maths problem to (6) _____ wasted significant amounts of time. Meyer said: "For situations involving more complex tasks, especially those requiring language, the total time taken to (7) _____ all the tasks done will increase greatly. Over long periods, this kind of multitasking can stress you out and lead to mental and physical exhaustion."