【单选题】对于圆管明渠水流,临界雷诺数取值为( )
【单选题】—Next week I' ll travel to New Zealand with my parents. —It's _____ . [ ]
【单选题】—Did Betty go shopping with you yesterday? —Even if she _____ a lot of studying, she would have preferred staying home to going shopping.
【单选题】–Would you like another cup of tea? –No, thanks. I ________ be off now. Rose is waiting for me.
【单选题】New Zealand is a large, long group of islands in the _______ Pacific Ocean.