古音学
参考答案:
古音又称上古音,古音学是对今音学来说的,它研究的对象是先秦两汉的诗歌韵文,而以《诗经》用韵为主要的根据,并且结合形声字,研究上古时期的汉语语音系统。
This summer holiday I did an English course which _____ for four weeks. [ ]
A. lasts
B. lasted
C. was lasted
D. were lasted
硬化水泥浆体的体积变化是由哪些因素引起的?这些因素是怎样使体积变化的?