问题
选择题
The coal miners in the coal mine for 10 hours before we came to their rescue.
A．had trapped
B．had been trapping
C．had been trapped
D．would have been trapped
答案
答案：C
考查时态。根据before we came to their rescue用一般过去时，故煤矿工人被困为过去的过去，故用过去完成时，选C。