A:was gathered
B:gathered
C:had gathered
D:has gathered
一 What happened to you? You look scared.
— Someone followed me all the way.
As the smallest child of his family, Alex is always longing for the time _______ he should be able to be independent.
老年痴呆症患者的脑血管中有一种特殊的β淀粉样蛋白体,它的逐渐积累可能导致神经元损伤和免疫功能下降,某些基因的突变会导致β淀粉样蛋白体的产生和积累。下列技术不能用于老年痴呆症治疗的是( )
①乙醇 ②醋酸溶液 ③水 ④盐酸.