A:黄河上游
B:长江上游
C:黄河中下游
D:长江中下游
执行如下图所示的程序框图,输出的结果是( )
① ____ A.
② ____ B.
③ ____ C.
④ ____ D.
⑤ ____ E.
The skin, an ________ part of your body and its largest organ, ________ as a barrier against diseases.
下列各句中,划线的成语使用不恰当的一项是( )