InKenya’svastTsavoNationalPark,breedingherdsofelephants...

問題詳情：

In Kenya’s vast Tsavo National Park, breeding herds of elephants are a common sight, the new babies hurrying to_______ their mothers.

   A. keep track of                         B. keep up with    

   C. keep in touch with                        D. keep away from

【回答】

B

知識點：詞組 短語

題型：選擇題