祖母【zǔ mǔ】
grandma; grandmother
[名]父亲的母亲——亦称“奶奶”

我小时候最爱听祖母讲神话故事。
I liked listening to the fairy tales told by my grandmother when I was a boy.
祖先【zǔ xiān】
1. ancestry; ancestor; forebear; forefather 2. forefather; progenitor (ancient organisms from which present-day livings or beings are evolved)
[名]1、民族或家族较早的上代 2、演化成现代生物的古代生物

中华民族的祖先主要在黄河流域生活。
The ancestry of the Chinese nation mostly lived in the Yellow River Valley.

据说我们的祖先是猴子。
It is said that our progenitors are monkeys.
钻【zuān, zuàn】
(zuān) 1. go through; dig into; drill (zuàn) 2. drill; auger 3. diamond
(zuān) [动]1、穿过 (zuàn) [名]2、钻孔的器具 [名]3、钻石

阳光只能偶尔从云层的缝隙中钻过。
The rays of sunlight occasionally pierce the clouds.

没有金刚钻,不敢揽瓷器活。
He who sups with the devil needs a long spoon.

我好像找不到我的钻戒了。
I can't find my diamond ring.