Complex sentence: Dr Wu was born in Penang, one of the three towns of the Straits Settlements (the others being Malacca and Singapore) which formed part of the colonies of Great Britain.
Split into simpler sentences: Dr Wu was born in Penang, one of the three towns of the Straits Settlements (the others being Malacca and Singapore). The Straits Settlements formed part of the colonies of Great Britain.