Some friends are curious.

"It was to honor the 50th anniversary of China Space. 9 years passed already."

"So it has a long history."

And I have another water cup of stainless steel with a longer history. It has been with me for at least 12 or 15 years. I owned it in my college time.

On its lid is there a knob fixed with a screw. The original screw was short, so became loose often. One holiday, my father found the problem. He proposed a solution silently and quickly. He replaced the short original screw with a long one from his tools box. Since then, no looseness happened. When I left for college, my mother told me it was my father.

"How is his solution?" mother asked.

"Good. I would't  been found if no one tells."

I didn't see any scene of his solving. But I can recover any details occurred. Saw the looseness, screened his tools box, took similar one and compared and tried, finally found a proper one, fixed, and nodded to be sure.

My father's screw is an ordinary one, rusted very soon. But the rust held the lid as a whole, so no problem in use.

Every moment I see the rust, I feel he is with us as ever.