()是研究的核心,又是明确的说明和规定课题。
A.操作性定义
B.实验
C.假设
D.变量
参考答案:C
Miss Liu wants to lose weight.She just has _______ cup of milk for ________ breakfast every day.
A.a;the
B.a;(不填)
C.the;a
D.the;(不填)
房地产开发企业应当在规划、设计变更确立之日起15日内,书面通知买受人。 ( )