问题
选择题
Martin Cooper , a US researcher , was considered _______ the first cell phone .
A．invented
B．to invent
C．having invented
D．to have invented
答案
答案：D
考查非谓语动词。sb be considered to have done sth认为某人过去做过某事。句意：Martin Cooper，美国研究者，被认为第一个发明手机，