—Tina, is this schoolbag? —Yes, it's mine. [ ]
A. his
B. her
C. Yours
D. your
答案:D
在20℃时,取NaCl和Ca(OH)2各10 g,分别与90 g水充分混合,所得溶液中溶质的质量分数为10%的是______.
颏部正中粉碎性骨折()
A.牙弓缩窄
B.前牙开牙合,后牙早接触
C.两者均有
D.两者均无