根据括号中所给的汉语写出单词，使句子意思完整正确，并将答案填写在标号为46~50 的相应位置上。

小题1:The YOG volunteers go for a meeting every    (星期日) these months. They hope to help the visitors from different countries better.

小题2:The sunglasses that the boy    (戴) just now are broken. He will buy himself a new pair.

小题3:The    （人口）of the world is increasing quickly. The earth is becoming more and more crowded.

小题4:Don’t complain about the weather, it will be much    (雾) tomorrow.

小题5:You can’t imagine how    (困难) he has finished his work.

大大加深了中国半殖民地化程度的不平等条约是（）