The research lacks evidence，and therefore，its conclusions are doubtful.
A．solid B．fierce C．severe D．potential
A good friend should be kind and helpful. _________ is my mother.
A. A such friend B. One such friend
C. Any such friend D. Such one friend
Though he is ill，he has not quit .
A．smoke B．to smoke C．smoked D．smoking
Evidence of a powerful volcano, which erupted under the ice sheet of West Antarctica around 325BC and might still be active now, __________ so far by British scientists.
A. confirmed B. has confirmed
C. is confirmed D. has been confirmed
The reason why the girl decided to leave her boyfriend was that she didn’t feel _________.
A. accurate B. secure C. unbearable D. adequate
Your as a student will be excellent if you develop a habit of reflecting on how you learn.
A．operation B．growth
C．performance D．character
