How Rocks Appear In Your Garden
I wonder how many of us （1）went out（过完） this past spring to get our gardens ready for planting, （2）smug（沾沾自喜的） in the thought that last year we got rid of all the rocks. There’s that nice big mound of them in the corner of the garden where we piled（堆砌） them. Surely by now they are all cleaned out.
“Wait! What is this?!” we said. A big stone, and another one, and another one! Where did they come from? Did some （3）mischievous（顽皮的，淘气的） kid bury a bunch of them for me to find this spring? Well, that could be, April Fool’s Day wasn’t that long ago. But maybe this time the kids were actually innocent.
Where The Rocks Grow
Any place that has winters cold enough to freeze the ground might experience the magical appearance of rocks （4）welling up（涌现） from beneath the surface. This is so common in the eastern U.S. that the rocks are called “New England potatoes.”
Here’s what makes these stones mysteriously appear. Stones are better conductors（导体） of heat than soil, so the stone conducts heat away from the warmer soil beneath it. That colder soil under the rock then freezes before other dirt at the same depth.
Remember that when water freezes it expands（膨胀）. So, when the water in the soil under the rock freezes, it expands and pushes the rock up a little.
When the ground （6）thaws（软化，解冻） a space is left under the stone which fills with dirt, so the stone rests a little higher. Over a period of time this repeated freezing, expanding, upward push, and filling underneath eventually shoves（推，撞） the rock to the surface.
She's gone out for a walk.
His cigarette has gone out.
This method went out long ago.
The year went out slowly.
You've got nothing to be smug about.
There's a mischievous look on her face.
Tears welled up in her eyes.
the conductor of an expedition 远征队队长
Copper is a good conductor of electricity.
The ice thawed in the sun.
It thawed early last spring.
He thawed after sitting at a fire for a while.
4.(态度、感情等)缓和, 随和, 更友好
His shyness thawed under her kindness.
The little girl's smile thawed the angry old man.
The spring thaw caused heavy flooding.
A thaw has set in.
Amy shoved the book across the desk to him.
He shoved his clothes into the drawer.
The surplus will shove the price down from a dollar to 60 cents.
He shoved at the car but it wouldn't move.
Everybody was pushing and shoving towards the exit.
The car won't start. Can you give it a shove?