我国年降水量分布的总趋势是( )
A:从东北向西南递减
B:从西北内陆向东南沿海递减
C:从西南向东北递减
D:从东南沿海向西北内陆递减
①听觉神经 ②听小骨 ③外耳道 ④大脑中的一定区域 ⑤内耳内的听觉感受器 ⑥鼓膜
我国目前许多地区水资源紧张,解决水资源季节变化大的最好办法是( )
Our teachers have been with us for nearly three years _______ we came to junior high school. We should thank them for what they have done for us.
人体呼气时,人体内相关结构的变化正确的是( )