The atomic weight of oxygen is_____than ______of the hydrogen.
| A．15 times heavier; that |
| B．15 times heavier: those |
| C．16 times as heavier; that |
| D．16 times as heavy; those |
The system has been designed to give students quick and easy to the digital resources of the library.
| A．access | B．passage | C．way | D．approach |
Form their ________ on the top of the TV Tower, visitors can have a better view of the city.
| A．stage | B．position | C．condition | D．situation |
Children need friendstheir own age to play with.
| A．of | B．for | C．in | D．at |
The ____________ shoes were covered with mud, so I asked them to take them off before they got into __________ car.
| A．girl’s; Tom’s | B．girls’; Toms’ | C．girls’; Tom’s | D．girl’s; Toms’ |
In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.
| A．signal | B．chance | C．mark | D．measure |