attempt to试图，企图

例句：Never attempt to fight a fire wearing a respirator or breathing apparatus.
      绝不要尝试在带着呼吸器或呼吸装置的情况下去救火。

2.By the end of the first year, most children are able to say a few simple words.

by the end of到…为止

例句：He had finished his great works by the end of 1980.
      到1980年底, 他已完成了他的巨著。