根据你的实验经验，下列几种金属投入到稀硫酸中产生氢气速度最快的是 [ ]
A.铜
B.锌
C.镁
D.铁
答案：C
已知集合A={x|x2-2x-3≤0，x∈R}，B={x|x＜1}，且A∩B=______．
Tom looked at Jenny, with tears______his eyes, and shouted out the words_______in his heart for years.[ ]
A. filling; having been hidden
B. filled; hidden
C. filling; hidden
D. filled; hiding
