问题
选择题
It is really a challenge for me to finish it. In order not to be disturbed, I spent three days ______ in my study surfing the internet to do the research.
A．locking
B．locked
C．to lock
D．lock
答案
答案：B
考查非谓语动词。本题考查短语spend … (in) doing sth.花费……做某事，根据句意选B。