英语谜语六 Riddles6

81.When is your uncle's sister not your aunt?
82.Mrs.Smith has nine children,half of them are girls. How can this be true?
83.Where can you never tell the truth?
84.What goes over the fields all day,and sits in the cupboard all night?
85.What walks around all day and lies under the bed at night with its tongue hanging out?
86.How many cheese sandwiches can you eat on an empty stomach?
87.When will a net hold water?
88.Why is a room full of married couples empty?
89.What table has no leg?
90.What tables grow in the fields?