听力原文： In the field of marketing，consumer goods are classed according to the way in which they are purchased．The two main categories are convenience goods and shopping goods．Two lesser types are specialty goods and unsought goods． People do not spend much time shopping for convenience items such as groceries，newspapers，toothpaste，razor blades，aspirin，and candy．The buying of convenience goods may be done routinely，as some families buy groceries once a week．Such regularly purchased items are called staples．Sometimes convenience products are bought on impulse，for example，someone has a sudden desire for an ice cream sundae on a hot day．Or they may be purchased as emergency items． Shopping goods are items for which customers search．They compare prices，quality，and styles，and may visit a number of stores before making decisions．Buying an automobile is often done this way． Shopping goods fall into two classes：those that are perceived as basically the same and those that are regarded as different．Items that are looked upon as basically the same include such things as home appliances，television sets，and automobiles．Having decided on the model desired，the customer is primarily interested in getting the item at the most favorable price．Items regarded as inherently different include clothing，furniture，and dishes．Quality，style. and fashion will either take precedence over price，or they will not matter at all． Specialty goods have characteristics that impel customers to make special efforts to find them．Price may be no consideration at all. Specialty goods can include almost any kind of product．Normally，specialty goods have a brand name or other distinguishing characteristics． Unsought goods are items a consumer does not necessarily want or need or may not even know about．Promotion or advertising brings such goods to the consumer's attention．The product could be something new on the market or it may be a fairly standard service．such as life insurance．for which most people will usually not bother shopping． According to the speaker，what are convenience goods?