单项选择题

The existence of point defects，impurity atoms, dislocations，grain boundary may all hinder the dislocation movement, hence weaken the materials

A.正确
B.错误
<上一题 目录 下一题>
热门 试题

单项选择题
In Polymers, bonds inside the long chain molecules are secondary bonding, bonds among the chains are covalent bonding
A.正确
B.错误
单项选择题
Primary bonding is the forces within a molecule, while secondary bonding is the forces between molecules
A.正确
B.错误
相关试题