| A city-state is a sovereign state, also described as a type of small independent country, that usually consists of a single city and its dependent territories. |
| Adjectives usually modify nouns, and adverbs usually modify verbs, adjectives, and other adverbs. |
| The fans are smaller, and are usually a combination of several moving and stationary turbines working in sequence to boost power. |
| Dust is removed from the airstream by the bag, and usually a filter, before it passes through the fan. |
| The chief executive of a central bank is usually known as the Governor, President or Chair. |
| People with bad eyesight usually need to wear corrective lenses, such as eyeglasses or contact lenses. |
