2013年英语四级习题及答案（9）：1. The lecture which lasted about three hours was so that the audience couldn't help yawning.A) tedious
B) boredC) clumsyD) tired，答案：A。
1. The lecture which lasted about three hours was so that the audience couldn't help yawning.
2. It you to at least 50% off the regular price of either frames or lenses when you buy both.
3. When carbon is added to iron in proper the result is steel.
4. There is a fully health center on the ground floor of the main office building.
5. Nancy is only a sort of of her husband's opinion and has no ideas of her own.