下列哪些句子可用于告知客户货物需延期交货？（多选题)
A、 We have contacted the shipping company and regret to tell you that we are unable to ship the goods before April
B、Owing to the unforeseen difficulties on the part of our manufacturers, we regret being unable to ship the goods with the time limit of your credit
C、We regret that these goods are not available at present
D、Please accept my apology for the delay which has been caused by the unavailability of shipping space from Guangzhou to London