苯丙素、木脂素、香豆素类化合物的合成途径是( )
A．乙酸-丙二酸途径B．甲戊二羟酸途径C．莽草酸途径D．氨基酸途径E．复合途径
参考答案：C
The little girl was too frightened _____ a word.[ ]
A. not to tell
B. not to say
C. to tell
D. to say
简述基本经济规律的地位和作用。
