签订: to agree to and sign (a treaty etc)...
动脉: artery...
回顾: to look back, to review...
钻: an auger, diamond...
大厦: (used in the names of grand buildings such as Broadway Mansions (in Shanghai) or Empire State Building etc)...
安稳: smooth and steady...
替: to substitute for, to take the place of, to replace, for, on behalf of, to stand in for...
修路: to repair a road...
同时: at the same time, simultaneously...
扳: pull; turn; switch...
