Question

choose the correct option scientist successfully started the clinical trials of human gene therapy since: options 1900:1990:1980:1970​

Answer 1

Explanation:

Concrete is manufactured using natural ingredients. Hence, it is environmentally friendly and recyclable. One can use crushed recycled concrete as the dry aggregate for preparing new concrete. As long as there are construction activities going on in the world, there will be a constant demand for concrete.