A:先天性行为
B:后天性行为
C:攻击行为
D:繁殖行为
用NA表示阿伏加德罗常数的值。下列叙述正确的是( )
Bill doesn't like the sunglasses in the ad because they can't __________ the sun well.
3654879____3654897 26900100000____27万
480÷12____480÷30 18×500____50×180.
读等高线图回答问题.