户外使用的防爆灯具外壳防护等级至少达到IP50以上。( )
参考答案：错
The driver was at______loss when________word came that he was forbidden to drive for speeding. [ ]
A. a; the
B. /; /
C. the; the
D. a; /
钻石信用卡的最高额度为人民币（）万元。
A.200
B.300
C.400
D.500
