Having devoted his life to the realization of racial equality，former South African President Nelson Mandela＿＿＿on December S，2013．
| A．passed away | B．had passed away | C．has passed away | D．passes away |
Tom asked the candy makers if they could make the chocolate easierinto small pieces.
| A．break | B．breaking | C．broken | D．to break |
In our class there are 46 students, _____ half wear glasses.
| A．in whom | B．in them | C．of whom | D．of them |
All the photographs in this book, _______ stated otherwise, date from the 1950s.
| A．unless | B．until | C．once | D．if |
The limits of a person’s intelligence, generally speaking, are fixed at birth, but ________he reaches these limits will depend on his environment.
| A．where | B．whether | C．that | D．why |
The police still haven’t found the lost child, but they’re doing all they .
| A．can | B．may | C．must | D．should |