产生促胰液素的细胞是
A．胃壁细胞B．胃主细胞C．小肠的上部S细胞D．胃肠粘液细胞E．胃窦粘膜G细胞
参考答案：C
The teacher told the students _____ in the Mid-term exam. [ ]
A. not cheat
B. not to cheat
C. cheated
D. should cheat
把0.000083用科学记数法表示为[ ]
A.8.3×10-4
B.83×10-4
C.8.3×10-5
D.83×10-5
