用方框中所给的单词的适当形式填空，每词限用一次.

nice    six      hear   have   safe

The winners are looking forward to ______________ from their friends soon
Cindy __________geography at 10:00 on Monday.
Everyone should learn to treat others ______________.
We were all worried about her ____________ during her journey to Africa.
The abacus was invented in the __________ century by the Chinese