您要查找的是不是：
- The state or quality of being null. 无效无效的状况或性质
- This layer of rock contains a lot of flint. 这一岩层中有大量燧石。
- The act of making null and void. 废除使 ... 作废和无效
- The inner layer of the wall of a spore. 孢子内壁孢子壁的内层
- There is a fine layer of dust on the desk. 桌子上有一层薄薄的尘土。
- The contract was null and void because it was not signed. 这个合同无效，因为它尚未签字。
- The middle, usually fleshy layer of a fruit wall. 中果皮果皮中间通常含肉较多的那一层
- The court ruled that the claim was null and void. 法庭裁决此项要求无效。
- The bottom layer is a mixture of sand and clay. 最下面的一层是沙和泥的混合物。
- A fine layer of dust covers everything. 所有的东西都盖了一层薄薄的灰尘。
- A layer, as of doubled-over cloth or of paperboard. 一层一层，如折叠过的布料或纸板的
- The marriage was declared null and void. 婚姻已宣告无效了。
- A surface, layer, or mass of frozen water. 冰面冻结的水的面、层或块
- A thin layer of bone, membrane, or other tissue. 骨骼、粘膜或其它组织的薄层
- The null subset corresponds to the term 1. 空集则对应于常数项1。
- A null reference pointer was passed to the stub. 向占位程序传送了空的索引指针。
- The agreement was declared null and void. 这个协议被宣布无效。
- A thin, flat layer or scale, as that of a fish. 外表组织薄而平的一层或鳞状物，如鱼鳞
- A promise obtained by force is legally null. 一个以武力获得的契约在法律上是无效的。
- The operator O is the null operator. 算符O是零算符。
