【判断题】标准麻花钻的横刃斜角为50°~55°。( )
【判断题】Different denatured DNA molecules can be combined into double-stranded renaturation after slow cooling.
【单选题】After infection of a cell by the HIV vires, a DNA copy of the viral genome may be inserted in the host chromosome This is an example of:
B.
disparate recombination
C.
homologous recombination
D.
nonhomologous-recombination
【多选题】电解加工可用在孔的加工和复杂成形模具零件中,如: