$1.$ Which type of test is designed to determine the endurance and reliability of an engine over time?

$-$ A$)$ Performance Test

$-$ B$)$ Durability Test

$-$ C$)$ Emissions Test

$-$ D$)$ Transient Test

$2.$ What does the specific fuel consumption $($SFC$)$ of an engine indicate?

$-$ A$)$ The fuel efficiency at a given power output

$-$ B$)$ The total fuel capacity of the engine

$-$ C$)$ The maximum fuel consumption rate

$-$ D$)$ The optimal fuel type for the engine