如何通过相互学习加深学习？
一国某年末外债余额50亿美元，当年偿还外债本息额15已美元，国内生产总值400亿美元，商品劳务出口收入55亿美元，则债务率为（）。 ["12.5%","13.8%","27.2%","90.9%"]
何为加工硬化？列出产生加工硬化的各种可能机制。（不必说明），加工硬化现象在工业上有哪些作用？
从发站至到站不需中转换乘的车票是：（） ["直达票","直通票","通票"]
Which two are characteristics of an IPv6 multicast address？（） ["First （most significant ） octet is FF in hex","Starts with a prefix of FE80 to FEBF in hex","Starts with a prefix of FECO to FEFF in hex","Second octet contains a 4-bit multicast scope field","Last 64 bit contains the modified MAC address of the Ethernet interface","Is allocated from the unicast address space"]
先定
