六、同学们正在谈论今天的天气。请选出每组单词中画线字母组合与句子中单词画线字母组合发音相同的一项。
()1. It's hot now. I'm thirsty.
A. this
B. think
C. their
()2. Thanks for your water.
A. that
B. thing
C. mother
()3. These boys are playing basketball in the sun.
A. there
B. three
C. both
()4. They like warm weather.
A. them
B. thirteen
C. thing
()5. The clouds in the sky(天空) are thin.
A. weather
B. birthday
C. brother

1.B 2.B 3.A 4.A 5.B

本题考查字母组合th的两种常见发音：清辅音/θ/、浊辅音/ð/，逐题辨析如下：
1. 句子单词thirsty的画线th发音为/θ/：A选项this的th发音为/ð/，B选项think的th发音为/θ/，C选项their的th发音为/ð/，因此选B。
2. 句子单词Thanks的画线th发音为/θ/：A选项that的th发音为/ð/，B选项thing的th发音为/θ/，C选项mother的th发音为/ð/，因此选B。
3. 句子单词These的画线th发音为/ð/：A选项there的th发音为/ð/，B选项three的th发音为/θ/，C选项both的th发音为/θ/，因此选A。
4. 句子单词They的画线th发音为/ð/：A选项them的th发音为/ð/，B选项thirteen的th发音为/θ/，C选项thing的th发音为/θ/，因此选A。
5. 句子单词thin的画线th发音为/θ/：A选项weather的th发音为/ð/，B选项birthday的th发音为/θ/，C选项brother的th发音为/ð/，因此选B。