It was not until 1938 _________ the first colour TV programme was broadcast.
Scientists have found no ________of life on Mars so far,though great efforts have made on the research.
A lot of people were made tired of the lecture which ________as long as four hours.
I have to amuse myself by looking after my 10-month baby since I have nothing important to work________these days.
It took the scientists seven days to________Takla Makan________“the sea of death”.
—Where did ________traffic accident happen,sir? —It took place at ________crossroads by the bank.