"Mom, the train is moving."
Yun Xiaoxiao patted their heads and explained, "The train has started. It moves by burning water in its boiler to create high-pressure steam, which drives the pistons in the steam engine to generate power, making the train go."
Da Bao and Xiao Bao didn't fully understand, but Zhao Tianlei got it.
His wife knew so much.
"Mom, if they don't burn coal, will the train stop?"
"Maybe in the future, we can develop other resources to replace coal and keep the trains running."
"Okay."
Yun Xiaoxiao looked at Zhao Tianlei, "Do you need to sleep?"
With two kids and their luggage to watch over, they had to take turns keeping an eye on everything. They couldn't expect him to look after it all alone.
"I'll go ask the conductor, you watch the kids."
He could manage a hard seat by himself; he was a grown man, after all.
But his wife and the little ones couldn't do that.
They certainly needed to sleep at night.
"Hmm..."
