家庭中病人或转移病员的途中,需要吸氧时均可使用氧气枕给氧。()
参考答案:对
________ regular exercise is very important, it's never a good idea to exercise too close to bedtime.[ ]
A. If
B. As
C. Although
D. Unless
从Windows环境进入MS-DOS方式后,返回Windows环境的DOS命令为【 】。