be knocking on the doorto be wanting to join a group or team – used in news reports 要求加入某团体[小组]〔用于新闻报道中〕 Five countries have permanent seats on the UN Security Council, but Germany and Japan, among others, are knocking on the door. 有五个国家拥有联合国安理会常任理事国席位，但包括德国、日本在内的其他国家也要求加入进来。
be knocking on the door• But a kiss denied, for Phillis was knocking on the door.• Soon Pugwash was knocking on the door.
→ be knocking on the door at knock1(2)