What is one sign that a topic sentence is ineffective? It is informative. It includes an opinion. It introduces a specific topic. It uses clear and concise language.

The correct answer is B) it includes an opinion.

A topic sentence is ineffective in that it includes an opinion.

Although you did not include any context or reference, we can answer in general terms.

So, A topic sentence is ineffective in that it includes an opinion. This is correct because when you write a topic sentence, this has to be validated by proper facts, numbers, or data from primary or secondary sources. An opinion is not a valid argument in topic sentences and you have to be very careful in not including one.

Remember that in writing, the topic sentence is very important because it introduces the idea of the paragraph.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.