下边对《天上的街市》中心意思的三种理解，你认为哪一种正确（    ）

下面语段空白处应填入的句子，恰当的一项是（    ）

       疑，常常是获得真知的先导，是打开知识宝库的钥匙。科学家李四光有句名言，“不怀疑不能见真理”。这句话颇为深刻。一般说来________而问题的解决，便是获得真知灼见的开始。数学家华罗庚之所以能在数学领域里取得一个又一个的优异成果，正是由于他对书本上现成的公式、定理和结论，能够大胆怀疑，科学释疑。他攀登数学高峰的第一步也就是从这里开始的。

Comets(彗星) are parts of our solar system. Like the planets, they go around the sun.
But comets are not made of solid rocks like planets. A comet is a ball of dust, stones, and ice. Many people call comets dirty snowballs.
The "snowball"may be only a few miles across. But when the sun heats the "snowball,"much of it is changed to gases. The gases spread out and form the comet's head, which may be thousands of miles across.
A comet moves fast in its trip around the sun. But when we see it, the comet does not seem to move. That's because it is so far away. The moon moves fast, but when you look at it, you can't see any motion(运动). That's because the moon is far away.
Each year astronomers(天文学家) discover new comets. Some of them are seen only once. They make one trip around the sun and then go away out into space. The sun's gravity cannot hold them.
Other comets, like Halley, keep returning. They have been captured by the sun. Halley's earliest visit was probably 3,000 years ago. It may keep returning for another 3,000 years.
But every time a comet goes around the sun, the comet loses part of itself. Gases and dust are pulled out of the comet. That's why Halley is now dimmer（暗淡的） than it used to be. Next time it visits us, in 2062, it may be even dimmer. Each visit it may get dimmer and dimmer, until it finally disappears.

下面横线上应填的最合适的一个词是（    ）

日长睡起无情思，________看儿童捉柳花。

下面横线上应填的最合适的一个词是（    ）

日长睡起无情思，________看儿童捉柳花。

下列各句中划线的成语使用恰当的一句是（    ）

在下面各项中前后的事物不存在比喻的关系的一项是（    ）

在下面各项中前后的事物不存在比喻的关系的一项是（    ）

在下面各项中前后的事物不存在比喻的关系的一项是（    ）