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UNIT 69 POPULAR SCIENCE (Ⅱ) Lesson 137 Part Ⅰ Warming-up Exercises Instruction-following: Square or Circle? 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Score: _______ Part Ⅱ Preserving The Environment Vocabu
Last time we talked about how astronauts eat and drink under weightless conditions in space. Today we'll cover the next question kids love to ask-how do astronauts go to the bathroom in space? It may sound silly, but it's really a good question, beca
It may sound silly, but its really a good question, because weightlessness does make a visit to the latrine a tricky proposition. Weightlessness poses two main problems in the bathroom. The first is that an astronaut could drift away from the bowl at
Lesson 62: [00:03.68]Take Short Showers!My name's Georgia. [00:09.53]Do you worry about pollution?I don't worry about it too much. [00:16.40]I live in Edmonton.Edmonton's a city in Canada. [00:22.57]It's a clean city.People don't throw their garbage
But we must leave the pin, for it is the pin itself that holds the parts together. 但是必须把大头针留下,因为两块东西就是让大头针来固定的。 Pins are made of many sizes, and are either black or white in colour. They are pre
Pollution: a Social Problem When we read newspapers, we often come across the word pollution. This word was not familiar to the people some decades ago. But now, it is a serious threat to us because.it means the poisoning of the air, seas, rivers an