Don't read books in bed,or it_____(be)bad for your eyesight.

问题描述:

Don't read books in bed,or it_____(be)bad for your eyesight.

will be
“别在床上看书,否则对你的视力有害.”
因为这个事情还未发生,只是假设而已,所以,用一般将来时态.