She insisted that she ______ not guilty , but we insisted that she ____ into prison

Swimming alone ____ be ____ dangerous. Do be careful.

My most devoted friend, Professor Yang, _______ often go hiking when he lived in the mountain that was covered with forest.

Although this ____ sound like a simple task, great care is needed.

—Shall I inform him of the change of the schedule right now? —I am afraid you _______,in case he comes late for the meeting.