劳动合同期限
参考答案：
是指用人单位与劳动者在劳动合同中约定的劳动合同履行期限，是劳动合同的必备条款。
I really wonder _______ will stop Japan from its annual whale hunt in the Antarctic. [ ]
A. that it is what
B. what it is that
C. what is it that
D. that is it what
干除灰斜槽内使用的透气层的层数为（）层。
A.3；
B.4；
C.5；
D.7。
