Jim managed to get into his house without the key. ___?
Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
He has the habit of ________ useful information while reading.
He left Wenzhou for Beijing last year, and we ________ him ever since.
When the boss got to the factory ________ midnight, he found it ________ ruins.
It is the first time that Mr. Smith ________ Wenzhou and I’d like to show him around.