在数轴上表示到﹣1的点的距离等于1的点表示的数是[ ]
A.0
B.1或﹣1
C.0或﹣2
D.﹣1
答案:C
维生素D缺乏性手足抽搐症的发病机制主要是()。
A.甲状腺反应迟钝
B.甲状旁腺反应迟钝
C.垂体反应迟钝
D.肾上腺皮质反应迟钝
E.肾上腺髓质反应迟钝
His friends found_____ to tell him everything that had happened.
A.it necessary
B.that necessary
C.it is necessary
D.necessary