ahead of的一个意思是“（在空间或时间上比某人或某事物）更前，更早。”如下面这则新闻的标题Israeli, Palestinians call for negotiations ahead of UN meeting. 另一个意思则是“处于（某人或某事物）的领先地位；比……更先进；领先”，比如His ideas were well ahead of his time. ；
keep still保持静止/别动；
as usual和往常一样；
further one's study 继续学习深造；
in one's opinion 依某人看来；
switch on接通,打开(旋钮)之类的；
figure out合计为, 计算出, 解决, 断定, 领会到;
stand for 代表；
wear and tear 磨损；
insert .... Into......把。。。。插入到。。。中