Don't use water to put out the fire if oil catches fire. As is known, oil ________ float on water.
A．shall
B．must
C．may
D．will
D
D 句意：如果油着火了不要用水来灭火，我们都知道油会浮在水的上面。will用于陈述真理性的事实。
情态动词的概念：
情态动词表示说话人对某一动作或状态的态度。
温馨提示：
