问题
单项选择题
学校作业越难，学习就越有效。有了这样的训练，会使学生在以后学习和工作中受益无穷。表现的是（）的基本观点。
A、形式训练说
B、相同要素说
C、概括说
D、奥苏贝尔的认知观
E、桑代克的联结说
答案
参考答案：A
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学校作业越难，学习就越有效。有了这样的训练，会使学生在以后学习和工作中受益无穷。表现的是（）的基本观点。
A、形式训练说
B、相同要素说
C、概括说
D、奥苏贝尔的认知观
E、桑代克的联结说
参考答案：A
| As viewed from space, the Earth’s distinguishing characteristics are its blue waters and white clouds. Enveloped by an ocean of air consisting of 78% nitrogen and 21% oxygen, the planet is the only one in our solar system known to harbor life. Circling the Sun at an average distance of 149 million km (93 million miles), the Earth is the third planet from the Sun and the fifth largest planet in the solar system. Its rapid and molten nickel-iron core give rise to an extensive magnetic field which, coupled with the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Most meteors burn up in the Earth’s atmosphere before they can strike the surface. The planet’s active geological processes have left no evidence of the ancient pelting it almost certainly received soon after it was formed. The Earth has a single natural satellite-the Moon. |
The main idea of this passage is that
A．there are life-supporting characteristics on the Earth.
B．the Earth is predominantly water.
C．the Earth has no common characteristics with other planets.
D．the Earth is the only planet with a moon.