National Zoo visitors can book passes starting Friday

Visitors of the Smithsonian's National Zoo can begin reserving timed entry passes this week ahead of the zoo's reopening on May 21. 

Zoo entry passes will be available online at 12:01 a.m. Friday.

New zoo exhibits include giant panda cub Xiao Qi Ji, Amur tiger Mitas, Przewalski's horse mother-son duo ...