Helen devoted herself ________to her research and became a top scientist in the field of applied physics[ ]

They _______him to drop the plan, but he was determined to carry it through to the end.

As a poet, Hai Zi used to write many romantic poems ______ people usually attach positive and hopeful meanings.

The whole area was________by the snow, and the government had to send food there by helicopter.

Everyone has periods in their lives ______ everything seems very hard.