Questions

Sound waves cannot be transmitted through vacuum. 

The hottest layer of the Earth is its innermost layer. The inner core Quite literally the center of the Earth, the inner core is solid and can get to estimate temperatures over 9,000 degrees Fahrenheit

VPN's are implemented to provide a secure connection through public networks. A virtual private network extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.

The Dhubai Metro(UAE) consists of two driverless lines(Red and Green) that totalled 74.694 km (46.41 miles) when the Greenline was officially opened on 9 September 2011.

Primary productivity refers to plants that make their own food using sunlight, water and availability of nutrients. Hence, they are not limited by time.