把下列句子合并成含有宾语从句的句子HewantstogobacktoEngland.Tomsays.ShewillleaveamessageonMrWu'sdesk.Shesays.Theytraveledbytrainlasttime.ihearShecan'tcometoday.ithinkwhereistheheadmaster?iwantto

　　把下列句子合并成含有宾语从句的句子

　　HewantstogobacktoEngland.Tomsays.

　　ShewillleaveamessageonMrWu'sdesk.Shesays.

　　Theytraveledbytrainlasttime.ihear

　　Shecan'tcometoday.ithink

　　whereistheheadmaster?iwanttoknowit.

　　hecan'tworkoutthisdifficultmathproblem.ithink

　　thestudentsofclassoneworkhard.theteachersaidtous

　　theearthisbiggerthanthemoon.theboysaidtous

　　thediversaidtothem.peoplehereliketotakebuses