27.The furnace of a oil fired boiler should be ____ before the operating burner is№

中国大学MOOC:"10. If you have something on the back burner, you will look at it later.";

​最早发现减毒活疫苗的科学家是​​​ A: Pasteur B: Koch C: Porter D: Burner E: Jenner

12. the hot pot of simmering broth on the portable burner in the middle of the table and put plates of meat, seafood, and vegetables around it. A: Set B: Setting C: Put D: Crash

首次将白喉外毒素给动物免疫，在动物血清中发现了抗毒素的科学家是（） A: Pasteur B: Burner C: Jenner D: Behring

a subordinate position A: silver lining B: recession C: dismal D: cervical E: back burner F: campaign G: binge H: H. outright I: I. disconcerting J: J. overall

a period of temporary economic decline during which trade and industrial activity are reduced A: silver lining B: recession C: dismal D: cervical E: back burner F: campaign G: binge H: H. outright I: I. disconcerting J: J. overall