维护失修棚的安全注意事项有（）
A.设专人监护
B.操作人员事先找好退路
C.站在支护完整地方
D.发现问题及时处理
参考答案：A, B, C
Though ______money, his parents managed to send him to a key university. [ ]
A. lacked
B. lacking
C. lacking of
D. lacked in
境外投资的积极因素是什么？
