The obvious issue is that the NULL check must be part of the while loop.

明显的问题是NULL检查必须放在 while 循环中。

youdao

Select the Loop check box.

选择Loop复选框。

youdao

Put the loop into manual mode. We need to check the transmitter.

把回路放在手动模式，我们要检查变送器。

youdao

Dad: Oh, cool. I need to check if we need to change from the Loop line to the line 1?

爸爸：噢，酷。我要核实一下我们是否需要从环线换乘到一号线。

youdao

Dad: Oh, cool. I need to check if we need to change from the Loop line to the line 1?

爸爸：噢，酷。我要核实一下我们是否需要从环线换乘到一号线。

youdao