帮忙找一道英语阅读理解题

Shopping is not as simple as you may think！ There are all sorts of tricks at play each time we reach out for that particular brand （品牌） of product on the shelf.

Colouring， for example， varies according to what the producers are trying to sell. Health foods are packaged （包装） in greens， yellows or browns because we think of these as healthy colours. Ice cream packets are often blue and expensive goods， like chocolates， are gold or silver.

When some kind of pain killer was brought out recently， researchers found that the colours turned the customers off because they made the product look weak and ineffective. Eventually， it came on the market in a dark blue and white package-blue because we think of it as safe， and white as calm.

The size of a product can attract a shopper. But quite often a bottle doesn't contain as much as it appears to.

It is believed that the better-known companies spend， on average， 70 per cent of the total c