—How’s your tour around the North Lake? Is it beautiful?—It _______ be, but it is now heavily polluted.
It was never clear ________ the man hadn't reported the accident sooner.(2011·江苏)
It doesn't matter ________ you turn right or left at the crossing—both roads lead to the park.
________ was most important to her,she told me,was her family.
It suddenly occurred to him ________ he had left his keys in the office.(2012·江西)
Have you noticed the problem ________ he is now in low spirits?________ come?