问题
选择题
Faced with nuclear pollution, we think it is time to ________ the trip to Japan.
A．call in
B．call for
C．call off
D．call on
答案
答案：C
词义辨析。call in叫某人进来；call for需要，要求；call off 取消；call on
号召。句意：面对核污染，我们认为是时候取消到日本的旅行了。所以选C。