－Do you know _______ World Water Day is?
－On March 22nd.
| A．when | B．where | C．what | D．which |
I didn’t know which shirt was better, the black one or the red one, so I took them.
| A．all | B．each | C．none | D．both |
--- Are you going to take part in the writing competition?
---________. It’s too good a chance to miss.
| A．That’s for sure. | B．Never mind | C．Cheer up | D．My pleasure |
Uncle Mike _______ to bed ______ he finished his work last night.
| A．not went; before | B．didn’t go; after |
| C．doesn’t go; until | D．didn’t go; until |
Scientists are working hard to make _______ possible for people to live on Mars in the future.
| A．it | B．that | C．this | D．one |
After you see the pictures, you will realize ______ danger the wildlife faces.
| A．how many | B．how often | C．how much | D．how long |