1. 用方框中所给单词或短语的适当形式填空，每个单词或短语限用一次。

wait for, proper, see, fix, main

1. （1） Please make sure the letter is addressed.
3. （2） The officers are the results of the opinion polls before deciding their next move,
5. （3） Little traffic can on the streets in China during the outbreak of COVID-19.
7. （4） Don't worry! Those workers the machine last night.
9. （5） The number of visitors here almost doubled last summer, because of the Music Festival.