A:32
B:12
C:cos70°
D:sin70°
有人设计下列实验步骤,用氯化钠固体配制50g5%氯化钠溶液,其中不必要的是( )
下列能在细胞核中发生转录的细胞是( )①有丝分裂中期的洋葱根尖细胞 ②精原细胞 ③高度分化不再分裂的神经细胞 ④人体内成熟的红细胞 ⑤效应T细胞 ⑥次级卵母细胞
I went to school without ____ (eat) anything this morning.
We don't have enough nurses to look after the patients. At least _____ are needed.