听力原文：M: Jane. shall we go through the inventory then？ Let's start with coal.
F: We have about 45 tons. But we are supposed to have 70 tons.
M: So we've got too little. We'd better order some more. How about gas？
F: I think we have enough stock for that.
M: OK, thank you then.
•For questions 1-8, you will hear eight short recordings.
•For each question, mark one letter (A, B or C) for tile correct answer.
•You will hear the eight recordings twice.
What is the recommended stock of coal？

A. 115 tons.
B. 45 tons.
C. 70 tons.