–Listen! Someone is playing ______ piano.
–Wow! What beautiful music! I like it very much
A:a
B:an
C:the
D:/
已知a→=(1,﹣32,52),b→=(﹣3,λ,﹣152)满足a→∥b→,则λ等于( )
①亲密无间,不分彼此
②遇到体力劳动要多承担责任
③言行举止要有分寸
④划清界限,互不接触