A:世卿世禄制
B:军功爵制
C:推举制
D:科举制
He said he was very sorry because it was _______ his power to make the final decision. _______, I had to turn to others for help.
若X-3在实数范围内有意义,则x的取值范围是()
下面关于细菌和真菌在自然界中的作用的叙述,不正确的是( )