are accepted， is accepted, accepted, speculate，serious, severe T

are accepted， is accepted, accepted, speculate，serious, severe The theory of black holes ________by many _______________ scientists and astronomers.
【正确答案】：is accepted, serious
【题目解析】：此句的意思是黑洞理论被很多严肃的科学家和天文学家所接受。主语是theory为单数所以用单数谓语且用被动态。Serious表示“严肃、认真”，severe意思是“严重的，剧烈的”。