She’s having a lot of trouble with the new computer, but she doesn’t know whom to____.[ ]

Pollution is a serious ___________ in China . PM2.5 has been increasing in recent years.

You see, my mum has promised to buy me ________MP4 next month—Oh, really? But I wish I could listen to music________MP3

Surely it doesn’t matter where the Students’ Association get their money from; what _________is what they do with it.

busy schoolwork, the children also have totake arts, music and sports classes in their free time.— I wonder what they will become.