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?