问题
选择题
_____ 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
答案
C
题目分析：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。