3.表示重复的动作

现在进行时用于少数瞬间动词，表示不断重复的动作。

Words and images are being sent throughout the world．Modern cellphones are more than just phones—they are being used as cameras and radios，and to send e-mail or surf the Internet．New functions are being added to the phones．(人教大纲版高一上第59页)

(手机)把文字和图像发到世界各地。现代手机不仅仅是电话机，它们也被当作照相机和收音机使用，还可以发送电子邮件或上网。新功能不断增加。

Wang Mei calls her best friend Xiao Liat least once a day to see how she is doing and what is going on．(人教大纲版高一上第59页)

王梅每天至少打一次电话给最要好的朋友小李，问候她并了解情况。

Scientists are also developing new fuels and engines that will let us travel without worrying about whether we are polluting the environment．(人教大纲版高二上第43页)

科学家还在开发新型燃料和新式发动机，使我们旅行时不必担心是否会污染环境。