题目内容
单词填空：根据所给括号中的词填空。
Later, he became ________ in science very much. (interest)
Look! How ________ Jim is laughing. (happy)
She didn't come to school yesterday because of ________. (ill)
I kept on ________ about the match. (think)
What will be the population of the world by the end of the ________ century?(twenty-one)
