to claw at sth/sb：向…抓去

• The wolf clawed at the tree and howled the whole night.

  那只狼在树上抓来抓去，嚎了一整夜。

• His fingers clawed at Blake's wrist.

  他用手指去抓布莱克的手腕。

• He stumbled, clawed wildly at the air and fell backwards into the water.

  他踉跄了一下，双手在空中乱抓，向后跌入水中。