is no doubt you have to remain seated and fasten your seatbelt before the plane lands.
A. There; whether
B. It; that
C. There; that
D. It; whether
网友回答
A. There; whether
B. It; that
(答案→)C. There; that
D. It; whether
解析：句意：毫无疑问，在飞机着陆前，你要坐着，系紧安全带。这里使用了固定句型：It is no doubt that…“毫无疑问…”，that连接的是同位语从句，如果是There is doubt后面用whether连接宾语从句，所以选C。