One of the following phenomena is rotation. Draw "√" in brackets.

I can't send pictures. pity

1. Left and right movement of window ()

2. The rotation of the electric fan blades ()

3. The elevator rope up and down movement ()

4. The wheels are rolling ()

Fill in the blanks as required.

Imagine a clock.

1. The pointer starts from "12", rotates 60 to () clockwise around the clock center at O point, and rotates 270 to () clockwise around the clock center at O point. ..

2. The pointer starts from "6" and rotates clockwise around the O point () to "10"; If the pointer is to rotate clockwise around the O point to "3", it needs to be rotated again ().

Third, draw the figure that the triangle AOB rotates 90,180 and 270 clockwise around the O point respectively.

Excuse me, here is a square piece of paper, horizontal 12 squares and vertical 6 squares. The triangle is a right triangle, the AB side of the triangle is horizontal, occupying two squares, and the AO side is vertical, occupying two squares.

Fourthly, if the line segment in the figure below rotates counterclockwise around point O 180, then the intersecting plane part can be regarded as a (); If the line segment in the figure below rotates 360 counterclockwise around the O point, then the swept plane part can be regarded as a ().

The picture is a horizontal line segment with no definite length, just a line segment.

All right, that's it. Typing is tiring. Although there is no picture, I still want to adopt ~