Strong tie between cut-wire pair and continuous wire in combined-structure metamaterials

► The 1st sentence in Section 2 is modified. ► The 6th sentence is added, and the 7th and the 9th sentences are modified in the 6th paragraph of Section 3. ► The 9th sentence is added in the 7th paragraph of Section 3. ► The 5th, the 6th and the 7th sentences are more clarified in Section 4.