下列何种细胞分泌促胃液素()
A、肥大细胞
B、Ecl细胞
C、G细胞
D、壁细胞
E、主细胞

单项选择题A charge is placed at the origin of a coordinate system and a charge is located at on the x-axis. The force on is found to be . A third charge is now placed at on the x-axis. What is the net force on now? A、0 B、 C、 D、

多项选择题下列关于味道敏感程度说法正确的有（ ）。