人的单眼皮和双眼皮是一对相对性状，决定双眼皮的基因为显性基因，决定单眼皮的基因为隐性基因．一家庭中，祖父和祖母都是双眼皮，其儿子是双眼皮，儿媳是双眼皮，孙子却是单眼皮．就决定单双眼皮这一性状的基因组成来说，下列各项叙述中，正确的是（    ）

从方框中选择恰当的词并用其适当形式填空。

Host: Welcome to 9 o'clock Weekend Talk.  We're talking to Bill,  a    ____     boy.  He is from US.  Hello,  Bill.  Welcome to the show.
Bill: Thank you. 
Host: You came to China five years ago.  Your Chinese must be very good. 
Bill: I practice    ____    it every day.  I  ____   reading Chinese stories and listening to Chinese songs. 
Host: Do you like to play   ____  ?
Bill: Yes,  I do.  And basketball is my favorite. 
Host: Really?  What do you    ____    baseball?
Bill: I love it,  too.  Lots of American boys love to play it.  
Host: Do you like to watch TV?
Bill: Yes,  I do. 
Host: What do you think of Soap Shows?
Bill: I   ____   them.  They are really boring. 
Host:    ____    Chinese Cooking?
Bill: I don't mind it.  ____   ,  my mom loves it. 
Host: How do you   ____    China? 
Bill: It's great.
Host: OK!  Thank you for    ____    us,  Bill ! 
Bill: You're welcome. 

下列关于北京人和山顶洞人之间不同的叙述中，正确的是（　　）

①居住地区不同

②体质特征不同

③取火方式不同

④装饰品不同

“不登高山，不知天之高也；不临深溪，不知地之厚也。”这表明（     ）。