Teenagers should ________ to take care of themselves from a young age.
A:educate
B:be educating
C:have educated
D:be educated
已知锐角△ABC中,边BC长为12,高AD长为8.
正常的听力可以使我们能够倾听万物美妙的乐章,用耳卫生是保障正常听力的前提.下列行为中可能会损失听力的是( )