He tried to join the army but was ______ because of poor health.
A:turned down
B:turned off
C:turned away
D:turned against
一天,一条大鱼问小鱼们:“在一个钓钩上挂着一条又肥又嫩、肉质鲜美的蚯蚓,你们认为不会上钩的最佳办法是什么?”下列回答中,你认为最合适的是( )
血液呈红色,主要因为它含有较多的( )