皮皮学，免费搜题
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【判断题】
如果第一层系统是1、2、3;第二层系统是1.1、1.2、1.3;第三层系统可以是2.1、2.2、2.3.A.
正确
B.
错误
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举一反三
【单选题】I bought a used Longman Dictionary yesterday. It ____ me only twenty yuan.
A.
spent
B.
cost
C.
used
D.
took
【简答题】配制和标定KMnO 4 标准溶液错误的是( ) A．采用直接配制法 B．KMnO 4 溶液需煮沸20～30min后，才可标定使用 C．用Na 2 C 2 O 4 做基准物进行标定 D．不需外加指示剂
【单选题】I bought some CDs for my friend and they _____ me ￥30. [ ]
A.
spend
B.
paid
C.
cost
D.
used
【单选题】I bought some CDs for my friend and they ______me 30 yuan. [ ]
A.
spend
B.
cost
C.
paid
D.
used
【单选题】I bought some CDs for my friends and they _____ me 30 dollars.
A.
spent
B.
paid
C.
cost
D.
used
【单选题】The used car I bought cost four _____ pounds.
A.
thousands
B.
thousand of
C.
thousands of
D.
thousand
相关题目：
【单选题】I bought some CDs for my friend and they ______me 30 yuan. [ ]
A.
spend
B.
cost
C.
paid
D.
used