我们经常使用的B-2949属于飞机的什么号？

In my opinion, all Mr Smith ____ good to his students in his class at present. He is very strict in their study.

The thing that ________ is not whether you fail or not, but whether you try or not.

It was very cold ____ they still went skiing.

I could not afford to rent a car like this,______buy it.

A boat made of steel costs more than ____ made of wood.

Very few experts have ____ with complete new answers to the epidemic problems.

The size of the customer, ____ we had expected, was well over one thousand.

There are many inconveniences that have to be ____ when you are camping.

A new technique ____ out, the yields increased by 20% .

I should like to try that boots on, but I don t know if it is my ____.