—Excuse me. Could you tell me _______?
—Yes. There is a video shop next to the tall building.
切洋葱时常会引起流泪,原因是洋葱细胞中含有对眼睛有刺激的物质,这些物质主要存在于( )
下列不属于青春期发育特征的是( )
据图中的实验常用仪器回答有关问题.