带式输送机使用液力联轴器的主要优点是()。
A.效率高
B.能起到过载保护作用
参考答案:B
— Excuse me, young man. Where is the park, please?
— It's across _____ the supermarket.[ ]
A. in
B. on
C. from
D. at
亲表皮现象(epidermotrophism)