It is hard for the Greek government to get over the present difficulties ____ it gets more financial support

from the European Union.[ ]

 A. if

B. unless

C. because

D. since

将两块导电金属片和钟表分别固定在一块木板上，两块金属片分别接通电池及雷管，并连接装药。用一根细绳捆结在一块金属片上和钟表的上闹铃发条的旋钮，拉紧绳子，两块金属片相接导电而引起爆炸，这是（）的特征。

A.电筒炸弹

B.钟表定时爆炸物

C.收录机爆炸物

D.瓶子自制爆炸物