sister [a female with the same father or mother as another person] I have only one sister.
sit [(1) to rest on the lower part of the body without the support of the legs; (2) to become seated] Please sit down and rest. (1) She sat down. (2)
situation [the way things are during a period of time] The situation in the Middle East is very dangerous.
size [(1) the space occupied by something; (2) how long, wide or high something is] Can you imagine the size of the Universe? (1) Geometry can help you measure the size of that big tree. (2)
skeleton [all the bones of a human or other animal together in their normal positions] Scientists sometimes find the skeletons of people who lived thousands of years ago.
skill [the ability gained from training or experience] He has great baseball skills.
skin [the outer covering of humans and most animals] Her skin was burned red by the intense sunlight.
sky [the space above the earth] The sky was filled with beautiful white clouds.
slave [a person owned or controlled by another] All slaves in the United States were freed by an amendment to the Constitution in 1865.
sleep [to rest the body and mind with the eyes closed] Do you sleep eight hours or more each night?
slide [to move smoothly over a surface] A big area of snow slid down the mountain.
slow [(1) to reduce the speed of; (2) not fast in moving, talking or other activities] Slow your speed to 45 miles per hour. (1) ＊one mile = 1.6 kilometers Is Special English slow enough for you? (2)
small [(1) little in size or amount; (2) few in number; (3) not important; (4) opposite large] The small boy was hungry. (1) The small force landed by parachute. (2) It was a small problem and easy to solve. (3) His small house was next to a big building. (4)
smash [(1) to break or be broken into small pieces by force; (2) to hit or move with force] He smashed the window with a rock. (1) The speeding car smashed into the wall. (2)
smell [(1) to sense through the nose; (2) something sensed by the nose] She smelled something burning. (1) I love the smell of food cooking. (2)
