1. yeast [jiːst]
n. Yeast is a kind of fungus which is used to make bread rise, and in making alcoholic drinks such as beer.
2. wreck [rek]
(1). v. To wreck something means to completely destroy or ruin it.
(2). v. If a ship is wrecked, it is damaged so much that it sinks or can no longer sail.
(3). n. A wreck is something such as a ship, car, plane, or building which has been destroyed, usually in an accident.
(4). n. A wreck is an accident in which a moving vehicle hits something and is damaged or destroyed.
(5). n. If you say that someone is a wreck, you mean that they are very exhausted or unhealthy.
The scandal wrecked the politician's chances of being elected.
3. incinerate [ɪnˈsɪnəreɪt]
(1). v. When authorities incinerate rubbish o waste material, they burn it completely in a special container.
(2). v. If people are incinerated, for example in a bomb attack or a fire, they are burnt to death.
The waste is incinerated in a large furnace.
4. topsoil [ˈtɒpsɔɪl]
n. Topsoil is the layer of soil nearest the surface of the ground.
The fieldstones remain in a frozen layer of topsoil.
5. emblem [ˈembləm]
(1). n. An emblem is a design representing a country or organization.
(2). n. An emblem is something that represents a quality or idea.
The dove is an emblem of peace.
整理自《柯林斯詞典》、《新東方託福詞彙》，侵刪歉。