release protect one another communicate average alive as well as calculate 1.He can speak English _______________ French. 2.Trees ______________ oxygen into the air which keeps people ______________. 3.Dolphins _______________ with each other by sound. 4.They looked after _______________ during the trip. 5.The car goes at a(n) _______________ speed of 90 kilometres per hour. 6.A pair of suitable shoes can _______________ you from being hurt while walking and running. 7.Trees produce oxygen. Scientists can _______________ the amount made each day.