中国大学MOOC: 重力式分离器gravitational separator工作原理operating principle：（）
中国大学MOOC: 重力式分离器gravitational separator工作原理operating principle：（）
On the surface of the moon, the gravitational force(重力) on a body is only 1/6 what it is here on earth.
On the surface of the moon, the gravitational force(重力) on a body is only 1/6 what it is here on earth.
Every body in the universe (宇宙) exerts a force of gravitational attraction (万有引力) on every other body (物体).
Every body in the universe (宇宙) exerts a force of gravitational attraction (万有引力) on every other body (物体).
中国大学MOOC: To help visualize what is meant by a gravitational field we may use lines of force. 下划线部分在句中作 。
中国大学MOOC: To help visualize what is meant by a gravitational field we may use lines of force. 下划线部分在句中作 。
根系主要吸收土壤中的（ ）水分。 A: 重力水（gravitational water） B: 毛孔水（capillary water） C: 吸湿水（hygroscopic water） D: 重力水和毛孔水
根系主要吸收土壤中的（ ）水分。 A: 重力水（gravitational water） B: 毛孔水（capillary water） C: 吸湿水（hygroscopic water） D: 重力水和毛孔水
Water attains the boiling temperature quicker in the high elevations than at the low level. Because: A: . the air pressure is lower at high elevations B: . the gravitational force is low in the mountains C: . the sunlight is high in the higher elevations D: . All of them
Water attains the boiling temperature quicker in the high elevations than at the low level. Because: A: . the air pressure is lower at high elevations B: . the gravitational force is low in the mountains C: . the sunlight is high in the higher elevations D: . All of them
Why is the second theory sometimes referred to as the Mars Theory A: Earth's moon used to orbit Mars. B: Mars was captured by the gravitational field of the Sun, C: A planet the size of Mars collided with Earth. D: Mars is larger than Eart
Why is the second theory sometimes referred to as the Mars Theory A: Earth's moon used to orbit Mars. B: Mars was captured by the gravitational field of the Sun, C: A planet the size of Mars collided with Earth. D: Mars is larger than Eart
中国大学MOOC: Which of the following transitional signal is the most appropriate for the sentence below?In physics, the weight of an object is the gravitational force with which Earth attracts it; __________, if a man weighs 150 pounds, this means that Earth pulls him down with a force of 150 pounds.
中国大学MOOC: Which of the following transitional signal is the most appropriate for the sentence below?In physics, the weight of an object is the gravitational force with which Earth attracts it; __________, if a man weighs 150 pounds, this means that Earth pulls him down with a force of 150 pounds.
Which of the following transitional signal is the most appropriate for the sentence below?In physics, the weight of an object is the gravitational force with which Earth attracts it; __________, if a man weighs 150 pounds, this means that Earth pulls him down with a force of 150 pounds. A: for example B: moreover C: therefore D: because
Which of the following transitional signal is the most appropriate for the sentence below?In physics, the weight of an object is the gravitational force with which Earth attracts it; __________, if a man weighs 150 pounds, this means that Earth pulls him down with a force of 150 pounds. A: for example B: moreover C: therefore D: because
According to the passage, what is the effect of Jupiter's other large moons on Europa（） A: They prevent Europa's subsurface waters from freezing B: They prevent tides that could damage Europa's surface C: They produce the very hard layer of ice that characterizes Europa D: They assure that the gravitational pull on Europa is maintained ar a steady level
According to the passage, what is the effect of Jupiter's other large moons on Europa（） A: They prevent Europa's subsurface waters from freezing B: They prevent tides that could damage Europa's surface C: They produce the very hard layer of ice that characterizes Europa D: They assure that the gravitational pull on Europa is maintained ar a steady level