what time ( ) sam go horseback riding (do or does)

只要主语是第三人称单数,如he,she,it,the boy,the desk等,谓语动词或助动词就要选用三单形式,如does,has,sings...如果有两个主语呢 比如 what time ( ) sandy and sam cook lunch? when 和 what time 和人称有关系吗and和both and连接两个主语看做复数，所以是do