—Shall I attend my friend's comingofage ceremony, Mum?
—No, unless you see to ________ that you will be home before 10：00 P．M.
| A．one | B．this | C．it | D．her |
It was never clear _______ the man hadn’t reported the accident sooner.
| A．that | B．how | C．when | D．why |
Barbara Jones offers to her fans is honesty and hapiness.
| A．Which | B．What | C．That | D．Whom |
It is uncertain____side effect the medicine will bring about，although about two thousand patients have taken it.
| A．that | B．what | C．how | D．whether |
The other day，my friend John drove his car down the street at _______I thought was a dangerous speed andsurprised everyone in the car.
| A．which，that | B．which，it | C．as，which | D．what，that |
The lack of eco-friendly habits among the public is thought to be a major ____ of global climate change.
| A．result | B．cause | C．warning | D．reflection |