Past Simple or Present Perfect. Exercises. Упражнение 1.Перепишите предложения в тетрадь. Раскройте скобки, употребив правильную форму глагола. Выделите слово-маркер и укажите время.
1. а) I (know) her for six years.
b) I (know) him when I was at school.
2. a) He (live) in Paris from 1997 to 2000.
b) He (live) in New York since 2001.
3. a) Where's Pete? I (not see) him for ages.
b) I (not see) Pete last night.
We can see waves on lakes or oceans. Waves are energy, not water. It is energy that moves across the ocean's surface. Water particles ony travel ina a small circle as a wave passes. Usually, the wind provieds the energy.. A strong wind that blows for a long time over open water can create big waves. Sometimes, an earthquake under the sea creates huge amounts of energy suddenly. This travels across the sea very quickly, then slows and grows is height when it reaches land.
We call the top od the wave the crest and the bottom the through. The distance between the crest and the throught is the wave height, and the distance between one crest and the next is the wave length.
Waves stop when the wind stops giving them energy to continue. Otherwise, they can travel to the other side of the world. On rocks, waves break with force, and create a lot of foam and spray. Ona a beach, the sand or stones slow the bottom part of the weave, and the crest rises to a peak, then curls over the top - creating the 'classic' wave shape - and breaks on the shore.