We were surprised to hear that the reason ________ she gave for her absence was ________ her mother was ill.—Yes.We saw her mother was at the supermarket that morning.

When Madam Cuirie did the science experiement again, she was more careful where she _____ a mistake

.The basketball match will be put off if it________.

The experts advise _______ our army _______ modern weapons.[ ]

No one knows when the house was built , but it must be very old.