heavy case

• 深渗碳层

heavy case的用法和样例：

例句

1. That looks a heavy case; let me lift it down for you.
   那只箱子好象很重; 我替你拿下来吧。
2. I humped the heavy case upstairs.
   我把那个沉重的箱子背到楼上。
3. The girl set her heavy case on the ground and took a rest.
   这个女孩把重重的箱子放在地上，休息了一会。