下列物质的用途,主要利用其化学性质的是( )
A:活性炭可除去冰箱中的异味
B:干冰用作人工降雨
C:氮气用作焊接金属的保护气
D:铜丝用作电线
给下列句子排序
____Thank you very much.
____Would you like some chicken?
____No, thanks. I can use chopsticks.
____Dinner's ready! Help yourself.
____Would you like a knife and fork?
____Yes, please.
____>____>____>____.
睾丸和卵巢都能产生( )