—Where is he exactly?
—I don’t know, but I saw him _______ an experiment in the lab when I passed by.
A. to conduct B. conducted
C. conducting D. conduct
The tourism of my hometown _______ a rapid growth over the last decade. Now it’s the 2nd most visited place in our city.
A. saw B. had seen
C. is seeing D. has seen
To his mind, the collaborative development of Beijing, Tianjin and Hebei province is to solve the problems _____ Beijing faces, such as overpopulation, traffic jams, and etc.
A. that B. whether C. when D. why
The houses for the low-income families _______ at present in our city will be completed next year.
A. to be built B. built
C. being built D. having been built
He spared no efforts to make himself _______ but failed.
A. understand B. understanding C. understood D. to understand
Jack, look! Everybody is doing homework quietly. ______ you make a noise in class?
A. Could B. Shall C. Will D. Must
