_______ I take part in a group discussion or try to speak English to someone, I find it difficult to express myself

(2013·咸阳二模)We should keep in mind that the earth is our only home and only by saving the environment________ourselves.

When I was passing the Town Hall, I heard the clock ______ twelve.

o friends are ________ related likethe lips and teeth, and you can often see them stay ________ together, hand inhand

They had a pleasant chat _____a cup of tea[ ]