The decision for or against a river crossing depends on a number of questions regarding both costs and engineering challenges.
The construction of the bridge's structure presented major engineering challenges.
The human exploration of Mars presents a massive engineering challenge.
Despite the simplicity of the materials, there were some engineering challenges.
The real engineering challenge is getting that cost down to where it's a mass-market product.
In addition to the engineering challenges, pioneers face uncertainty about their legal rights.
It's a seemingly simple idea that has proved to be an extraordinary engineering challenge.
Running of the first metro car on the line by 1984 was considered a great engineering challenge.
From the beginning, the Citigroup Center was an engineering challenge.
Do they really believe that a new spacecraft will come without an engineering challenge or a human toll?
