A:her
B:him
C:his
细胞核分裂时,染色体先进行____,再____到两个新细胞中去,保持亲代与后代具有____的遗传物质。
It is often the case ______anything is possible for those who hang on to hope.
交警用装有重铬酸钾(K2Cr2O7)的检测仪检测司机是否酒后驾车。K2Cr2O2中Cr的化合价为()