[填空题]Weather (permit)（）,we will go hiking the day after tomorrow.

Life on earth depends on the sun. Day after day we see its light and feel its {{U}} (36) {{/U}}, but we do not often know or {{U}} (37) {{/U}} the birth or the beginning of their {{U}} (38) {{/U}}. Yet there are amount of {{U}} (39) {{/U}} things about the sun. One is its distance from the earth. This is about ninety-three {{U}} (40) {{/U}} miles. It is to us, a long distance. A {{U}} (41) {{/U}} of this distance, even if it could be made, would take {{U}} (42) {{/U}} hundred years even in the {{U}} (43) {{/U}} rocket.
The sun makes us feel heat, even at a distance of ninety-three million miles. This is not surprising. {{U}} (44) {{/U}}. But we receive only a small part of this heat. The total heat of the sun could melt a column of ice two and a quarter miles thick and ninety-three million miles high in one second.
The brightness of the sun is equally astonishing. As we said earlier, we receive only a very small part of t