Learning about outer space Daniel is writing about visiting another planet. Help him rewrite the sentences using the words in brackets.
1 Neil Armstrong took his first flight when he was only six. (at the age of)
2 Yuri Gagarin became the first man to go into outer space at the age of 27. (when)
3 People might move to another planet in the future because the population on the Earth is increasing rapidly. (because of)
4 If there is no fresh food, meals will not be as tasty as they are today. (without)
5 It would be funny to play football on Mars because of the low gravity. (because)
6 Without special boots, you cannot walk on Mars. (if ... not)
1 Neil Armstrong took his first flight when he was only six. (at the age of)
2 Yuri Gagarin became the first man to go into outer space at the age of 27. (when)
3 People might move to another planet in the future because the population on the Earth is increasing rapidly. (because of)
4 If there is no fresh food, meals will not be as tasty as they are today. (without)
5 It would be funny to play football on Mars because of the low gravity. (because)
6 Without special boots, you cannot walk on Mars. (if ... not)
答案：1 Neil Armstrong took his first flight at the age of 6.
解析：“when he was only six”可以用“at the age of 6”替换，表达“在6岁时”。
2 Yuri Gagarin became the first man to go into outer space when he was 27.
解析：“at the age of 27”可以转换为“when he was 27”，用when引导时间状语从句。
3 People might move to another planet in the future because of the rapid increase in population.
解析：“because the population on the Earth is increasing rapidly”可以用“because of the rapid increase in population”替换，“because of”后接名词短语。
4 Without fresh food, meals will not be as tasty as they are today.
解析：“If there is no fresh food”可以用“Without fresh food”替换，“without”表示“没有”。
5 It would be funny to play football on Mars because the gravity is low.
解析：“because of the low gravity”可以转换为“because the gravity is low”，用because引导原因状语从句。
6 If you do not wear special boots, you cannot walk on Mars.
解析：“Without special boots”可以转换为“If you do not wear special boots”，用if引导条件状语从句。
解析：“when he was only six”可以用“at the age of 6”替换，表达“在6岁时”。
2 Yuri Gagarin became the first man to go into outer space when he was 27.
解析：“at the age of 27”可以转换为“when he was 27”，用when引导时间状语从句。
3 People might move to another planet in the future because of the rapid increase in population.
解析：“because the population on the Earth is increasing rapidly”可以用“because of the rapid increase in population”替换，“because of”后接名词短语。
4 Without fresh food, meals will not be as tasty as they are today.
解析：“If there is no fresh food”可以用“Without fresh food”替换，“without”表示“没有”。
5 It would be funny to play football on Mars because the gravity is low.
解析：“because of the low gravity”可以转换为“because the gravity is low”，用because引导原因状语从句。
6 If you do not wear special boots, you cannot walk on Mars.
解析：“Without special boots”可以转换为“If you do not wear special boots”，用if引导条件状语从句。