在做双缝干涉实验时.用白光做光源,将在屏上得到彩色条纹,若在双缝的—条缝前放置红色滤光片(只能透过红光),而另一缝前加绿色滤光片(只能透过绿光),则这时( )
A_____is a person who is in someone's home by invitation,for a short time,as for a meal,or to stay one or more nights.( )
A.bossB.customerC.guest
﹣Good news!Metro Line 11will be open on June 30 in our city.
﹣Great!It will make our lives more convenient.( )
A.richerB.easierC.faster
﹣Excuse me,could you please tell me the way to the Book City?
﹣OK.Walk along this street till you reach the Children's Palace.The Book City is opposite it.( )
A.on the other side ofB.in front of
C.next to
﹣My mum is ill.I have to stay at home and look after her.
﹣I'm sorry to hear that.I hope she can get better soon.( )
A.look atB.look forC.care for
﹣A little giraffe has come to Shenzhen Safari Park.Shall we go and watch it?
﹣Good idea!Let's go there togethernext Sunday.( )
one by one
with each other
in our spare time