What does this rebus mean?

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Two guards were guarding the camp.Guard-1 was looking towards the south to make sure no threat is coming from the road.Guard-2 was looking at the north to make sure no threat is coming from the top. Suddenly Guard-1 ask the Guard-2 why he is smiling?How Guard-1 knows that Guard-2 is smiling?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Decode below rebus
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S , D

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

Count the Triangle in the figure given below:

Solve the following series:
AZ, GT, MN, __, YB

In the image given, you can find several triangles. Can you count them all?

I look at you, you look at me I raise my right, you raise your left. What am I?