How much difficulty has the team had_______ this problem—_______．The members are all good problem solvers.

The old lady, _______ had been killed in the war, was given help by the local government．

下列句子中，没有语病的一项是（ ）

What’s this A pen—– ______, a pencil.

It is clearly stated that regulations __________ everyone in the community, without exception.