Sentences

1. When water freezes in the cracks of rocks, it expands, causing the rocks to break apart. 
2. The quantum theory states that energy, such as light, is given off and absorbed in tiny definite units called quanta or photons. 
3. According to anthropologists, the earliest ancestors of humans that stood upright resembled chimpanzees facially, with sloping foreheads and protruding brows. 
4. Not until 1866 was the first successful transatlantic cable finally laid. 
5. The flatter a hair appear under a microscope, the wavier it is. 


6. The windmill to pump water and grind grains had at least been fully accepted. 
7. The spiral threads of a spider's web have a sticky substance which traps insects.