concave sucking disc

例句：

1. 1. The car'sroof is made of a concavematerial that can be folded up for storage.
   这辆车的车顶是用一种可以折叠起来的凹面材料制成的。
2. 2. Theconcave shape ofthe moon reflects light in away that makes it look larger thanit actually is.
   月亮的凹面形状使得它看起来比实际更大。
3. 3. Theconcave surface of the bowl is smoothand easy to hold.
   碗的凹面表面光滑且易于握持。