Has Russia ever apologized for stealing nuclear secrets from the United States during the Manhattan Project?

No.  Any more than the USA would apologize for keeping it secret from its wartime ally.

Note also that the main source was information given freely by scientists who felt the secret needed to be shared.

Note that Germany was widely believed to be close to having its own atomic weapons.  If they had possessed one, the most logical use would have been to bomb Moscow and hope to destroy the Soviet leadership.  So the USA could and should have warned of the possibility, and did not.
What does the average student pay for college tuition?

It depends on where they go and if they are full-time/part-time.For public, in-state full-time tuition and fees, the College Board reported an average of $3,780 for 2017–18, for full-time private nonprofit it was $14,500. Source: Average Net Price over Time for Full-Time Students, by Sector

How does tipping work in Japan? Do I tip for meals? For taxi rides?

I remember when I was in Japan, I left the change equivalent to a little less than a dollar at a kiosk because I was in a hurry. As I started running to hopefully catch the next train, the cashier lady began shouting,

In your opinion, will exercise actually improve someone's health?

Exercise can help you look better. ... In fact, exercise can help keep your body at a healthy weight. Exercise helps people lose weight and lower the risk of some diseases. Exercising regularly decreases a person's risk of developing certain diseases, including obesity, type 2 diabetes, and high blood pressure.Moderate exercise, such as walking, can reduce