_______ provides many hours of air for astronauts in space.
| A．An air tank | B．A power pack | C．A helmet | D．A space sleeping bag |
Food safety is important. Rulesto stop people from food pollution.
A、must make B、must be made C、can’t be made
Shein a toy factory, but now she has a shop of her own.
A、is used to work B、was used to work C、used to work
I can’t wait ____ the present box.
| A．open | B．to open | C．opening | D．opened |
The box is ________ heavy ________ I can’t lift it.
| A．too, to | B．very, that | C．so, that | D．too, that |
Everyone is supposed ________ a seat belt in the car.
A. wearing B. to be worn D.wear D. to wear