2. Take a closer look at the following sentences, and correct any mistakes involved. (1) Modern irrigation techniques are more efficiency than traditional ones. (2) Poor diet can lead to a number of healthy problems. (3) After 3 weeks the average high of the plants increased by 12.6 centimetres. (4) Sells of ice-cream usually increase significantly in the summer. (5) The danger of driving too fastly in urban areas was highlighted in the report.