高曾祖父

例句：

1. 1. He has a great grandfather who lived to be 90 years old.
   他有一位活到90岁的曾祖父。
2. 2. My grandfather's father was my great grandfather.
   我祖父的父亲是我的曾祖父。
3. 3. The family tree is traced back to the great grandfather of our forefathers.
   家族树追溯到我们祖先的曾祖父。