显示指定文件的前若干行的命令是()。
A.less
B.tail
C.more
D.head
参考答案:D
When I was thirteen, my family moved from Boston to Tucson, Arizona. ... Finally, we arrived
and _____ into our new home. [ ]
A. settled
B. walked
C. hurried
D. stepped
按要求写出下列反应的文字表达式,并注明反应的基本类型.
(1)点燃镁条作信号弹:______.
(2)燃烧红磷制造烟雾弹:______.
(3)燃烧木炭:______.
(4)高锰酸钾受热:______.
(5)过氧化氢与二氧化锰混合:______.