单项选择题T8钢（共析钢）过冷奥氏体高温转变产物为（）。A、珠光体、索氏体、上贝氏体B、珠光体、上贝氏体、下贝氏体C、珠光体、索氏体、铁素体D、珠光体、索氏体、屈氏体
单项选择题Being able to determine the main idea of a passage is one of the most useful skills that can apply _____ any kind of reading. A.on B.in C.for D.to
