The plane is flying ____ a speed of 500 kilometers an hour ____ the way to Kunming.
This chemical material is very toxic. So put it ______ the children’s reach.
The central heating system of this office building is down and several workers ______ it right now.
China's present environment situation is from bad to worse and if we _________ now to protect the environment, we’ll live to regret it.
In recent years the consumption of aspirin _______ enormously in America. A was increasing B. has increased C. had increased D. will be increasing
–Would you be kind enough to help me with my homework at one o’clock this afternoon? -- . Will two o’clock be OK?