下列实验中有化学反应发生，且能观察到明显现象的是（ ）
A．向氯化钾溶液中滴入稀硫酸
B．向硫酸钠溶液中滴入氯化锌溶液
C．向氧化铜粉末中滴入氢氧化钠溶液
D．高温下向氧化铁粉末中通入一氧化碳
--Do you still remember the days ________ we spent in the country?
--Yes, of course, they were peaceful and relaxing.
| A．where | B．when |
| C．who | D．that |
There is no dictionary _______you can find everything.
| A．that | B．which | C．where | D．in that |
Three years has passed, but we can’t forget the people _________ helped me a lot in the past.
| A．which | B．whom | C．who | D．whose |
He is one of the cleverest students ________ hard work was paid in the end.
| A．who | B．whom | C．whose | D．that |
Great Britain is one of the countries ____ people drive on the left.
| A．where | B．that | C．which | D．there |