一直 vs 总 vs 总是

He kept talking for two hours. (He did not stop talking.)

Each time it rains, his leg is always painful. (He often feels the pain in his legs.)

She has been singing this song all these days. (The action takes place repeatedly. )

He kept missing home all these years. (The state continues.)

Go straight to the north, you'll see Peking University.

People from the age of 10 to the age of 80 like this character very much.

Don't worry, you'll pass the exam at last.

Although I'm running slowly, I'll make it to the finish line at last.

We waited all day long, no matter what happens we need to see the manager.

Either go climbing or have a picnic, we need to wait until the rain stops.

Until now, we ran at least 10,000 meters.

You've been talking on the telephone for a long time, at least one hour.