rectify
vt.纠正，修复
I did my best to rectify the situation, but the damage was already done.我竭尽全力整顿局面，但损害已造成。
recur
vi.再发生，重现
There is a danger that the disease may recur.这种病有复发的危险。
specialize
vi.(in)专门研究，专攻
Simmons specialized in contract law.西蒙斯专攻合同法。
species
n.种，类
Seven species of birds of prey have been observed.观察到了七种猛禽。
