a double dissolution
【正确答案】：①A double dissolution is the dissolving of both Houses of Parliament by the Governor-General at the request of the prime minister.
②This occurs when a bill has been passed by the House of Representatives and rejected by the Senate, and, after three months have elapsed, again passed by the Representatives but rejected by the Senate.
③A general election may then be called in an attempt to solve the deadlock.
④This procedure inevitably involves a lot of delay.
【题目解析】：
参见教材P300。
