A.only a very small part is available
B.the sun is too distant from the earth
C.it takes thousands of years for this energy to be stored up in coal and oil
D.our scientific knowledge is not sufficient
单选题 | He had to give up ___ the football match because he had his leg injured in the accident. | 查看答案 |
单选题 | John Light bought the “Lusitania” _______. | 查看答案 |
单选题 | If everybody is _______, let’s begin our class. | 查看答案 |
单选题 | On his return from his college, he found the house ________. | 查看答案 |
单选题 | The wheel is important because _______. | 查看答案 |
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单选题 | Which of the following statements is NOT true? | 查看答案 |
单选题 | Why can’t astronauts drink water from cups? | 查看答案 |
单选题 | My parents never let me _______ alone. | 查看答案 |
单选题 | In order to grow well, the Blue Sprace, like other pine trees, ______ a temperate climate. | 查看答案 |
单选题 | The reason why all the solar energy falling on the earth can’t be utilized is that ______. | 查看答案 |
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单选题 | Something always _______ wrong when we try this recipe. | 查看答案 |
单选题 | The wheel is called _______. | 查看答案 |
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单选题 | The word “surface” in the passage means the ______. | 查看答案 |
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