大学英语：alarm n. 惊恐;担心;闹铃 v. frighten (使惊恐;向…报警)

　　2.alarm n. 惊恐;担心;闹铃 v. frighten (使惊恐;向…报警)

　　alarming adj. worrying， disquieting (使人惊恐的、令人担心的)

　　1)There is no cause for alarm. (不必恐慌。)

　　2)It is necessary that you install a burglar alarm.(你有必要装防盗警报器。)

　　3)They were alarmed to find the old lady dead.(他们发现老太太死了，大惊失色。)

　　4)The world's forests are shrinking at an alarming rate.(世界森林正以惊人的速度减少。)