问题
选择题
To prepare for the Olympic Games in summer, London ____ its largest ever exercise to test the response of emergency services.
A．planned
B．is planning
C．had planned
D．plans
答案
答案：B
考查时态。根据句意：为了准备今年夏天的奥运会，伦敦正在计划一个有史以来最大的锻炼来检查对紧急服务的回应。