准分子激光角膜原位磨镶术(LASIK)(如图)治疗近视时,切削角膜的()
A.周边区基质
B.旁中央区基质
C.中央区基质
D.中央区浅表组织
E.旁中央区浅表组织
参考答案:C
There is _____ snow. Put on your coat. It's _____ cold today. [ ]
A. too much, much too
B. too many; much too
C. much too; too much
皮肤划破而流血,但不久后自然止血,这与下列哪一项有关[ ]
A.白细胞
B.红细胞
C.血小板
D.上皮细胞