阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。

    ____ (exact) when the first people arrived in what we now know as California，no one really knows. However, ____ is likely that Native Americans were living in California at least fifteen thousand years ago.

    Scientists believe that these first settler ____ (cross) the Bering Strait in the Arctic to America ____ means of a land bridge which existed in prehistoric times. In the 16th century, after the ____ (arrive) of Europeans, the native people suffered greatly. Thousands were killed or forced into slavery. In addition, many died ____ the diseases brought by Europeans. However, some survived these terrible times, and today there are more Native Americans ____ (live) in California than in any other state.

    In the 18th century, California was ruled by Spain. Spanish soldiers first arrived in South America in the early 16th century. Two centuries later, the Spanish had settled in most parts of South America and along the northwest coast of ____ we now call the United States. Of ____ first Spanish to go to California, the majority were religious men, whose ministry was ____ (teach) the Catholic religion to the natives.