___A__of his time ___been spent on studies every day
A ,Three fourths :has
B ,Three fourths :have
C,Third fours:has
D,Thirds four :have
解析：分数用“基数词＋序数词”表示,复数形式在序数词后面加s.分数百分数作主语时,关键看后面名词是否可数来决定单复数,time 不可数,故选A.
祝开心~!