Jenny was a little nervous in front of so many strangers at  first. But when she glanced at Jack,

she immediately   felt _____ .   [ ]

A. in peace  

B. in need      

C. at a loss    

D. at ease

在数据库设计器中设计表之间的联系时，要在父表中建立【 】，在子表中建立【 】。