债券远期交易从成交日至结算日的期限由交易双方确定，但最长不超过（）
A、3个月
B、6个月
C、2年
D、365天
参考答案：D
His parents, ________, did not look after him very well: the elbows of his jacket and his boots were badly worn. [ ]
A. generally
B. gradually
C. actively
D. apparently
利用采煤机在工作面两端约（）m的范围内斜切进刀称为端部斜切法。
A、15~20
B、20~25
C、25~30
D、30~35
