In the past month, cruel snowstorms hit some European countries and America , _________great transportation problems in these countries.
A．causing B．caused C．to cause D．having caused
With Halloween approaching, there exists a real concern among parents and teachers __________ trick or treating will become a seriously anti-social activity.
A. whether B. what C. that D. how
When first __________ to the market, the computer software was not a success due to its complexity in operation.
A. introducing B. being introduced
C. introduced D. to be introduced
Unfortunately, the element Madam Curie devoted all her life her death .
A. to caused B. causing C. to be caused D. to causing
Out of the crowded bus , who was dressed in a black suit and waved to a woman.
A. a tall man in his thirties stepped B. stepped a tall man in his thirties
C. did a tall man in his thirties step D. did a tall man step in his thirties
— I want someone to write the composition for me.
— No. As a student, you ________ depend on yourself.
A. shall B. will C. can D. may
