DNA分子的______结构能够为复制DNA提供精确的模板,通过______原则保证了复制的准确进行,DNA分子的这种复制方式称为______。
双螺旋 碱基互补配对 半保留复制
Only when I put myself in their position ________ they were more miserable than me.
A.I had known
B.had I known
C.I knew
D.did I know