炎炎夏日,我们通常吃西瓜解渴。切开西瓜时,会发现有许多红色的汁液流出。这些汁液主要来自于西瓜果肉细胞的( )
( ) Why is he _____? A. cry B. crying C. laugh
()Why are you ____ at the sky ? A. look B. looks C. looking
()It’s easy to _____ mistakes with English words. A. make B. makes C. making
()They ____ the caps on . A. put B. puts C. putting
()What’s _____ the bag? A. into B. in C. at