以下来源于髓样干细胞的血细胞是()
A.红细胞、粒细胞
B.T细胞、NK细胞
C.血小板、单核细胞
D.巨核细胞、NK细胞
E.粒细胞、B细胞
参考答案:A,C
If you are going to stay in the United States for longer than a(n) ______ visit, you may be interested in learning more about its people and culture.
A.formal
B.regular
C.brief
D.unexpected
在一个减法算式中,差与减数的比是4:5,被减数与减数的比是( ):( )。