胃、十二指肠溃疡病人出现大量呕吐物、顽固、定时呕吐，提示病人可能发生（）
A.急性穿孔
B.幽门梗阻
C.溃疡出血
D.肠壁破裂
E.癌变
参考答案：B
图所示的电路中，S闭合时，下列说法中正确的是
A.L1和L2并联，电压表测灯L1两端的电压
B.L1和L2并联，电压表测灯L2两端的电压
C.L1和L2串联，电压表测灯L1两端的电压
D.L1和L2串联，电压表测灯L2两端的电压
Last week our geography teacher told us _____ more information about how to protect the environment. [ ]
A. get
B. got
C. to get
D. getting
