8. /first time/ he/ see/ fire/ probably/ when/ tree/ strike/ lightning. A The first time he saw fire was probably when a tree was struck by lightning. B The first time he saw fire probably when a tree was struck by lightning. C The first time he saw fire was probably when tree was struck by lightning. D The first time he saw fire was probably when a tree struck by lightning. 49. He/ soon/ learn/ make/ fire/ himself/ rub/ two/ stick/ together. A He soon learned how to make fire by himself by rubbing two sticks together. B He soon learned how to make fire for himself with rubbing two sticks together. C He soon learned how to make fire for himself by rubbing two sticks together. D He soon learned how to make fire by himself with rubbing two sticks together. 50. Fire/ very important/ man/ because/ he/ need/ fire/ keep/ warm/ night,/ cook/ food,/ and frighten/ enemies and wild animals/. A Fire was very important to man because he needed fire for keep warm at night, cook food and frighten away enemies and wild animals. B Fire was very important to man because he needed fire to keep himself warm at night, cook food and frighten away enemies and wild animals. C Fire was very important to man because he needed fire to keeping him warm at night, cooking food and frightening away enemies and wild animals. D Fire was very important to man because he needed fire by keeping his house warm at night, cooking food and frightening away enemies and wild animals. 51. Red Indians,/ example,/ use fire/ make/ smoke signals,/ people/ lit/ fires/ warn/ friends/ danger/ other countries. A Red Indians, for example, used fire to make smoke signals, so people lit fires to warn their friends of danger in other countries. B Red Indians, for example, used fire to make smoke signals, but people lit fires to warn their friends of danger in other countries. C Red Indians, for example, used fire to make smoke signals so that people lit fires to warn their friends of danger in other countries. D Red Indians, for example, used fire to make smoke signals, or people lit fires to warn their friends of danger in other countries. 52. Fire/ very also use/ give light,/ such/ burn sticks/ torches/ before/ invention/ oil lamp. A Fire was very also used to giving lights, such as burn sticks as torches before the invention of oil lamp. B Fire was very also used to give lights, such as burn sticks as torches before the invention of oil lamp. C Fire was very also used to giving lights, such as burning sticks as torches before the invention of oil lamp. D Fire was very also used to give lights, such as burning sticks as torches before the invention of oil lamp. 53. And before/ man/ discover/ gas and electricity,/ hang/ small fire/ wire basket/ post/ light/ streets. A And before a man discovered gas and electricity, he hung small fires in wire baskets at posts to light up the streets. B And before a man discovered gas and electricity, he hung small fires on wire baskets at posts to light up the streets. C And before a man discovered gas and electricity, he hung small fires in wire baskets from posts to light up the streets. D And before a man discovered gas and electricity, he hung small fires on wire baskets from posts to light up the streets.