the shot in the arm 激励；鼓舞
A：Good news!B：What is it?A：The state of economy is starting to go up in our country.B：That’s just the shot in the arm we need.A：好消息！B：什么消息？A：我们国家的经济状况开始好转了。B：那正是我们所需要的鼓舞人心的消息。
