Tom often goes to school ______ John. ( )
A:in
B:on
C:with
Nowadays, more and more students choose to take a gap year. That is, they take a year ____ between the ending of high school and the beginning of university.
19世纪60年代,欧洲基督教神权统治的根基遭到沉重打击。主要是因为( )
既能分泌激素,又能分泌消化液的是( )
奥斯特实验说明了____;通电螺线管附近小磁针如图所示,则电源的a端是____极(选填“正”或“负”).