rib, or an annular rib consisting of multiple protruding points; and an inner rib of the barrel body is disposed on the inner wall of the barrel body below the stopping rib of the barrel body, wherein the distance between the stopping rib of the barrel body and the inner rib of the barrel body is greater than or equals to the thickness of the annular pre-stopper piece and the inner diameter of the stopping rib of the barrel body is smaller than the diameter of the annular pre-stopper piece.
Reference Document 2, with Patent No.: ZL200720067715.4, by Application Date: 2007 Mar. 8, with Issued No.: CN201076648, the patentee thereof: Shanghai Dingjiantang Biochemical Technology Co., Ltd., has disclosed “a plunger with a metal hook” comprising a plunger body, aCIA names first woman to lead Directorate of Operations

In a surprising departure from established practice, the United States Central Intelligence Agency has publicized the name of its incoming head of operations. Beth Kimber, a 34-year veteran of the Agency, will become the first woman in the CIA’s 70-year history to lead the Directorate of Operations. Officers in the Directorate of Operations, formerly known as the National Clandestine Service, spend their careers recruiting foreign agents to spy for the United States, while also carrying out covert operations around the world. This is also the first time that the CIA has chosen to publicly identify its Deputy Director for Operations —Kimber’s official title, abbreviated as DDO. Previous DDO have been undercover officers whose namse have remained undisclosed. Kimber’s promotion was