1. But a single optical fiber with a diameter of less than half a millimeter can carry more information than a large cable made of copper wires.
    但是单单一根直径小于半毫米的光纤电缆就可以比由铜丝制成的粗电缆负载更多的信息。

2. The silicon chip is less than a millimeter thick.
    这个硅片还不到一毫米厚。