重点讲解：
1. for sure 无疑；肯定；
例句：Nobody knows the cause of the fire for sure.
没有人确切地知道大火的原因。
2. all the time 一直；始终；
例句：It seems that prices keep going up all the time.
物价似乎总在上涨。
3. point out 指出，说出（事实或错误）；
例句：I didn't point out what he was really after.
我没有点破他的真实意图。
4. tie up (用线或绳)固定，扎牢，捆紧；
例句：He tied up the packages well with heavy cord.
他用粗绳子把那几包东西结实地捆好。
