【题目】In order not to be heard, she pointed her finger upwards to ____ that someone was moving about upstairs.
A.whisper
B.signal
C.declare
D.complain

【答案】B
【解析】句意：为了不被听到，她手指向上指，示意有人正在楼上走动。A项“低声说，私语”；B项“发信号，（用手势）示意”；C项“（正式）宣称”；D项“抱怨”。故选B项。