The questions here want to test your knowledge of English plural, singular and uncountable nouns. They are testing this by seeing whether you make the verb agree with the subject noun phrase.
The noun rain is usually uncountable and would take a singular verb. However in weather forecasts, when we are talking about it raining at different times in different places, we sometimes talk about heavy rains, which is plural. So in example (1), we need:
Heavy rains have caused flooding in several parts of the south west.
In the second example, the word news looks like a plural form because it ends in S (it has plural morphology). In addition, in many languages the word for 'news' is plural—for example the word noticias in Spanish. But in English, the word news is uncountable, even though it looks plural. We need singular verb agreement. So example (2) should read:
Today's news is all about the approaching hurricane.
Some other nouns that look plural but are usually uncountable/singular in English are:
Some subjects: mathematics (and in British English maths), physics, electronics, politics, ethics etc
Some sports and games: billiards, darts, tiddlywinks etc
Some place names: Brussels, Wales, Athens, the Netherlands etc
Some illnesses, diseases and medical conditions: rabies, rickets, mumps, measles, the bends etc
In English we also have some countable nouns whose singular and plural forms both end in S. They take singular or plural verb agreement, depending on the meaning:
- a kennels, two kennels
- a species, two species
Other common words like this include: means and crossroads.