The order urged the armed forces to enhance their alertness.该项命令敦促武装部队提高警惕。A dog's protective instincts are manifested in increased alertness.狗的自我保护本能表现在它的警觉性越来越高。The drug improved mental alertness.这种药可以提高大脑的注意力。The drug improved mental alertness.该药有助于提神。