_________ water to grow is well-known. A. That trees need B. These trees need C. That tree needs D. Trees need 答案:A 解析: 本句的意思是:树需要水生长是众所周知的。 That trees need water to grow是一个主语从句,放在句子的开头,引导词that不能省略。质量相等的氢气和氧气,温度相同,不考虑分子间的势能,则( )A.氧气的内能较大B.氢气的内能较大C.两者内能相等D.氢气分子的平均动能较大