The number of reported crimes is increasing at an alarming rate.

　　報(bào)警案件的數(shù)量正在以驚人的速度增長(zhǎng)。

　　The speed at which cities are growing in the less developed countries is alarming.

　　欠發(fā)達(dá)國家城市發(fā)展的.速度令人擔(dān)憂。

　　The disease is spreading with alarming rapidity.

　　這種疾病正在以令人吃驚的速度蔓延。