A model or an experiment in a science class can help students see things which would ______ remain hidden.
| A．otherwise | B．still | C．thus | D．therefore |
It was only when I read this story for a second time________to appreciate its beauty.
| A．did I begin | B．that I began | C．then I began | D．had I begun |
. The doctor was so kind that he devoted all his spare time he had _______the poor boy.
A. to helping B. helped C. helping D to help
Tom said he did not mind what time I arrived at his place____I promised to go and help him.
| A．on condition that | B．so far | C．as well as | D．as good as |
Yao Juan is the only one of the students who_________to be praised.
| A．are | B．have been | C．is | D．has been |
The experts advise______our army_________modern weapons.
| A．to equip; with | B．equipping; with | C．to equip;for | D．equipping; for |