4. A circle of radius 1 rolls along a straight line from the point $K$ to the point $L$, where $K L=11 \pi$. Which of the following pictures shows the correct appearance of the circle when it reaches $L$ ?
4. D The circumference is $2 \pi$, so every time the circle rolls $2 \pi$ it has turned $360^{\circ}$ and looks the same as it did at $K$. After $11 \pi$, it has turned $51 / 2$ turns, which is picture $\mathrm{D}$.