點解咁樣用is 及 are

1) Our company headquarters (is) in London.

- headquarters is not a plural of 'headquarter', its a noun by itself
- therefore the use of (is) is right

2) The statistics in the report (are) inaccurate.

- in the sentences, the (are) is for (statistics), not (report), the sentence could be trim into : The statistics are inaccurate

3) This species (is) green and white spots

-again, (species) is not a plural noun, so use (is) rather than (are)