According to Darwin's Survival of the Fittest, only those species that were able to ______ the sudden great changes of their living conditions survived.

______the weather, our school sports meet has to be held in the indoor stadium.

It took      people as well as      time to build the pyramid.

I remember it in my heart forever that success       anyone who has the most realistic dreams.

The Qing Tombs are obviously influenced by the Ming Tombs, especially _________architecture and their choice of site among the mountains and valleys.

Where and when the meeting is to be held ______ our headmaster.

Tom raised his hands    to say something, but he remained silent in the end.

As he _______ , he was surprised to see that the man had disappeared.

After climbing the hills in the natural park for hours, my legs _   under me and I failed to keep pace with others．

In such a background, his white hair was particularly      his dark skin．