阅读短文，从下列单词中选择适当的词或词组并用其正确形式填空，使短文通顺、意思完整。(每词或词组限用一次。)

small    be    make    although    such as

Do you know that scientists can put time into a small chip (芯片)? Recently, Chinese scientists have made the world’s smallest atomic (原子能的) clock. It ____1____ so small that it looks just as big as a coin.

____2____ the clock is small, it can tell time clearly and correctly. Over more than 30,000 years, its error is still less than one second! Earlier, similar clocks from other countries were 17 cm³. But the new clock from Wuhan University is only 2.3 cm³, much ____3____.

It looks tiny, but it is very useful. It can be helpful in modern science and technology, ____4____ man-made satellites in space, drone groups in the sky and underwater machines in the sea.

China has made great progress in ultra-precise (超高精度的) timing technology. Now scientists can ____5____ this kind of clock in large numbers. It will also be used in other high-tech fields in the future.

1.1.

A

B

C

D

解析：选is。句意：它如此小，看上去只有一枚硬币那么大。固定结构such…that/so…that；本句是so…that句型，主语It是第三人称单数，一般现在时，be动词用is，故填is。

2.2.

A

B

C

D

解析：选Although。句意：虽然这个钟体积很小，但它能够清晰精准地计时。前后分句为让步关系，although引导让步状语从句，句首首字母大写，故填Although。

3.3.

A

B

C

D

解析：选smaller。句意：但是武汉大学这款新原子钟仅有2.3立方厘米，要小得多。much后面修饰形容词比较级，前文对比别国17 cm³，新的体积更小，small的比较级是smaller，表示更小的，故填 smaller。

4.4.

A

B

C

D

解析：选such as。句意：它在现代科技领域很有用，例如太空中的人造卫星、空中无人机群以及海里的水下设备。such as用来举例，表示例如，故填such as。

5.5.

A

B

C

D

解析：选make。句意：现在科学家们可以大批量制造这种原子钟。情态动词can后面接动词原形，make表示制造，故填make。