For some years after his graduation, he()some of his classmates, but as times went by, he dropped them one by one
A. caught up with
B. kept in touch with
C. kept up
D. made up with
查看答案
计算机病毒侵入系统后,一般不立即发作,而是等待“时机”发作,这种特性叫作()。
A. 潜伏性
B. 表现性
C. 传染性
D. 隐蔽性
人体吸入煤气出现头痛、头晕、呕吐、全身无力属()。
A. 轻度中毒
B. 中度中毒
C. 重度中毒
D. 中毒
第五套人民币2005年版100元、50元纸币均保留了1999年版100元、50元纸币()种专业防伪特征
A. 3
B. 4
C. 5
D. 6