Also, for no apparent reason, dark spots often appear to be accompanied by light spots.

ECONOMIST: Comparative meteorology

Confusion happens because, on the visible surface, both types of investing often appear to be the same.

FORBES: What's the Difference Between Private Equity and Venture Capital?

Gen Ys often appear not to be listening.

FORBES: Gen Ys! You Will Listen!

The historian Eric Hobsbawm famously claimed that British traditions "which appear or claim to be old are often quite recent in origin and sometimes invented".

BBC: Define Britishness? It's like painting wind

Because viruses often read people's address books, they will appear to be from known individuals.

CNN: Technology - Analysis: Understanding viruses

Older children and adults who have whooping cough often appear to have a bad cold or persistent cough that can be so severe that it causes vomiting.

CNN: Can breast-feeding prevent whooping cough?

Since Friday, Japanese officials have often minimized the danger posed by the crippled nuclear reactors, which appear to be in various stages of melting down.

FORBES: Third Explosion Rocks Japanese Nuclear Plant; Radiation Levels Rise

It's not often that journalists are invited to appear before lawmakers to plead their case, so Matthew Cooper of Time magazine could be excused for seeming a bit uncomfortable in the formal hearing room of the Senate Judiciary Committee.

NPR: Judiciary Committee Considers Reporter Shield Law

Often, the symptoms of ASD appear as extreme shyness or anxiety in girls, masking that they may not be responsive to the social cues of others.

CNN: How girls and boys differ when it comes to autism