煤气泄漏会引起什么危险?遇到这种情况应该怎么办?
构成自然景观地区差异的主要因素是( )
在△ABC中,A=120°,AB=4,若点D在边BC上,且BD→=2DC→,AD=273,则AC的长.
—There is milk but there is bread.
—Let's get some bread.