In a microbarograph,the pen should be chec
题型:单项选择题
问题:
In a microbarograph,the pen should be checked and the ink well filled().
A.each time the chart is changed
B.once per month
C.once per week
D.daily
In a microbarograph,the pen should be checked and the ink well filled().
A.each time the chart is changed
B.once per month
C.once per week
D.daily