คำแปล ความหมาย ของ "pH" ที่ค้นพบ

When investigating the pH (acidic, neutral, alkaline) of a liquid, don't soak the litmus paper completely in the liquid but just put the end of the paper in it.

When Hawking graduated from college in 1962, he began studying for a Ph.D. in physics.

I have to work for my Ph. D. this summer.