重点讲解：
1. a number of 若干；许多；
He's been around a long time and has acquired a number of skills.
长久以来他见过很多世面，学了很多技术4v9yq~pSCwg@qyXm]。
2. aim to do sth. 致力于；旨在；以…为目标；
They are aiming to reduce unemployment by 50%.
他们正力求使失业人数下降50%Q@|PU%F(]VEmJ0,6rN。
3. prevent sb. from doing sth. 阻止；阻碍；阻挠；
Nothing would prevent him from speaking out against injustice.
什么都不能阻止他鸣不平D6IC.#_G_Mge&O0924aD。
4. accuse sb. of sth./doing sth. 指责；责难；
She accused him of lying.
她指责他说谎tOfSAY(ihR!P4phj[。