根据句意及首字母提示补全单词,使句子完整、通顺.
1.Yesterday no one c___________little David form school,so he had to go home by himself.
2.-Last week my dog was lost,but it r_______by itself last night.
-It is really a clever dog!
3.The forecast says that the t_______will fall to zero degree this evening.
4.Peter is good at computer,so he has no t________with the new computer system.
5.Ann is too fat,so she keeps running every day now to lose w______.