Special entrances _____ buildings should be constructed ______ the convenience of the old and disabled[ ]

It is important to understand the crime’s nature to prevent crimeAs we know, most crimes are about things, not ____ the persons

Large quantities of water, as well as some other timely help including a medical team ___ since the serious drought hit Yunnan Province. [ ]

It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it．

My father had ____ me a new computer as my birthday present. [ ]