哺乳动物细胞基因导入法常用的有______、______和______。
参考答案：显微注射法、 脂质体载体法、磷酸钙沉淀法
He was driving so fast as to get himself into a dangerous situation _____ he is likely to lose control over
his ear.[ ]
A. where
B. how
C. why
D. which
简述一下下填料管的浮简起到什么作用。如何完成工作的？
