问题
选择题
AIDS control and prevention is a to China as well as the whole world．
A．surprise
B．challenge
C．reaction
D．threat
答案
答案：B
考查名词辨析：A．surprise 惊讶，B．challenge挑战，C．reaction反应D．threat威胁，句意是：艾滋的控制和预防对中国乃至全世界都是挑战。选B。