Questions

An Umbrella.

Yes, when it is open it can't be fit under a chimney but when it is closed it can be fit down a chimney.

Competition  occurs when two or more organisations act independently to supply their products to the same group of consumers.

There are mainly two cases when firms can compete. One is price where firms are selling identical or very similar products, they must compete on price with each firm trying to undercut the others. The other is differentiation. A non-price competition depends on making a product different from those of competitors and by giving it distinctive qualities that are valued by the target market. This might include branding, styling, special features or higher levels of customer service. Good competition provides more options to customers and also brings with it improved  customer services.

 Capital of Kazakhsthan is Astana

The correct pairing of DNA bases among the given options is guanine - cytosine.

Capital of Niger is Niamey

A search engines are a software systems used for searching about any information in the world on the web.

Search engines like Google, Bing, Internet explorer, Yahoo, etc... functions by providing relevant search results for the keywords user searches. 

Hence, the given statement is TRUE.

The Sahara is the biggest desert in the world.

It occupies the northern one third of the African continent.