______, vowels tend to be nasalized before nasal consonants because it is difficult to time the lowering of the velum to produce nasality with the consonant articulation.
A、Physiologically
B、Psychologically
C、Culturally
D、Sociologically
【正确答案】：A
【题目解析】：Physiologically, vowels tend to be nasalized before nasal consonants because it is difficult to time the lowering of the velum to produce nasality with the consonant articulation.