In communication,a smile is usually ________ strong sign of a friendly and ________ open attitude. (2011·重庆,26)
--- John is said to have written two books last year.一Yes, so he__.They are both about the Second World War.
Vitamin D gets produced when animals are exposed to direct sunlight, for_reason, itis always advisable to give them chances to spend time in the sun.
In the middle of February, the weather__favorable for work, the workers began to repair and secure the dam of the river.
The local guide told the explorers that ropes and knives were__wanted to go into the inner part of the mountain must take along.
In many cities of China, if an ambulance is__in a traffic jam, police will respond to the emergency.