81．We are looking for someone who is_____(可靠的) and hard-working．

80． He is so s__________ that no one can persuade him．

79． There is an ___________(表情) of anger on his face now．

78． Passengers are kindly r__________ not to smoke in the bus．

77． His interest in this subject will increase __________(逐渐地)．

　　　　　 根据题中所给的汉语或首字母写出符合句意的单词的正确形式。

76． The boy is too young to draw a ______(笔直的) line on the paper．