— ________. He seemed interested in my experience, but he didn't ask for my recommendation letter.
A:Perfect
B:I'm not sure
C:That's right
D:Couldn't be better
等质量的氮气和氧气中,所含分子数较少的是____
6 C
12.01
7 N
氮
14.01
8 O
氧
16.00
小兵说:“从前往后数,我排第____,从后往前数我排第____。
—Isn't it in your bag? I saw you ____ it in your bag.
—Oh, here it is. Thank you.