Read the text and for questions 1-8 choose from the brain technologies (A-D). Which brain technology 1) is a very small device? 2) will be able to work at a high speed? 3) allows research without experimenting on humans? 4) has already been in use for a number of years? 5) will solve a problem users experience with a current type of technology? 6) can aid scientists researching brain function? 7) could help people who cannot use their limbs? 8) is known for helping someone speak?