The Nuclear Security Summit is an initiative of Mr. Obama, considers nuclear terrorism to be one of the greatest threats to international security.
| A．which | B．what | C．who | D．whom |
His parents both died in the traffic accidents, ________ him a lot of debts.
A．having left |
B．left | C．to leave | D．leaving |
Wouldn’t it be ______ wonderful world if all nations lived in ______ peace with one another?
| A．a; / | B．the; / | C．a; the | D．the; the |
--- I’m not good at singing, you know.
--- ________! It’s just for fun.
| A．No problem | B．Come on | C．What a pity | D．Cheer up |
Have you ever been to Mount Huangshan, ___________is famous for its pine forests and "seaof clouds"?
| A．what | B．where | C．that | D．which |
writing the article, Mrs. Curie even forgot her dinner.
| A．Absorbed in | B．Absorbing at | C．Having absorbed by | D．To absorb in |