Questions

Sound waves cannot be transmitted through vacuum. 

When exports are greater than imports, net exports are positive and similarly, when imports are greater than exports, net exports are negative.

When a country imports goods, it buys them from foreign producers. The money spent on imports leaves the economy, and that decreases the importing nation's GDP.

Protein synthesis take place in the cytoplasm where ribosomes are located as they are the machinery which are responsible for the protein synthesis.

The supply curve slopes upward because for reflecting the higher price needed to cover the higher marginal cost of production. 

Humming bird is the smallest bird and the only bird which can fly in backwards in the world.