The resulting steel appears to achieve a combination of strength andtoughnessthat is comparable to that of modern steels that are very rich in alloy content and, therefore, very expensive.
2019年6月六级真题（第三套）阅读 Section A
The resulting steel appears to achieve a combination of strength andtoughnessthat is comparable to that of modern steels that are very rich in alloy content and, therefore, very expensive.
The resulting steel appears to achieve a combination of strength andtoughnessthat is comparable to that of modern steels that are very rich in alloy content and, therefore, very expensive.
The resulting steel appears to achieve a combination of strength andtoughnessthat is comparable to that of modern steels that are very rich in alloy content and, therefore, very expensive.