Let's talk performance. With C and D we have two places where we can use different implementations that influence performance for DisplayManager objects, or better access. But you might not always have the full freedom to pick all the options.
公安机关及其人民警察办理治安案件，不严格执法或者有违法违纪行为的，任何单位和个人都有权向公安机关或者人民检察院、监察机关检举、控告；收到检举、控告的机关，应当依据职责及时处理。，更多细节参见PDF资料
plain contrasting background，这一点在新收录的资料中也有详细论述
Australia’s 3-3 draw with South Korea means they finish second in Group A and must travel to Perth for their quarter-final。新收录的资料对此有专业解读