中国大学MOOC: 6. Flip turn is the only method of turning in the water.
举一反三
- If water freezes，it （ ）ice A: will turn into B: turns into C: is turning into D: Is going to turn into
- Only 3 percent of the world’s water is fresh water. The rest _______ salt water. A: be B: am C: is D: are
- The single turn method of returning to a man overboard should be used only if _________.
- Walk for two blocks and then __________(turn / turning) left. A: turn B: turning
- Water wheels are machines that use the energy of ______ to turn a wheel. The axle of the turning wheel can then power other machines to do work.