Hewastoldthatitwouldbeatleastthreemoremonths__________hecouldrecoverandreturntowork.
A.whenB.beforeC.sinceD.that在线课程B
解析：
it was some time before…是一个很有用的句型，其字面意思是“在……之前过了一段时间”，通常可转译为“要过一段时间才会……”，如：It will be five years before we meet again. 五年以后再见。It may be a matter of months before it’s ready. 要准备好可能得数月时间。