下列各组中,互为同位素的是( )
A.D2O和H2O
B.SO2和SO3
C.O2和O3
D.235U和238U
答案:D
We feel some _____ before we take an exam, so the teacher always asks us to do some exercise
to make us relaxed. [ ]
A. tension
B. conflict
C. secure
D. superb
在株洲美食一条街的牌匾和玻璃窗上,来自成都的小刚和小明看到 “鲁菜”、“川菜”、 “粤菜”、“湘菜”等招牌,如果他们想吃家乡菜,应该进挂哪种招牌的店
A.鲁菜
B.川菜
C.粤菜
D.湘菜