— Where does water on land go in the end?
— It flows into seas or oceans ________ lakes and rivers.
A:past
B:with
C:across
D:through
下列哪项做法对青少年的神经系统的健康有害( )。
操场上跳绳的有15人,踢足球的有7人,打篮球的有9人。