题目内容：

    Every time you use a tea bag, you could be absorbing billions of microplastic and nanoplastic particles (纳米塑料颗粒). That's the conclusion of researchers at McGill University in Montreal.

The research centred on four different types of tea bags, of the kind recently preferred by some premium (优质的) brands. Having been emptied of the tea itself, the bags were placed in water heated to 95℃.

Researchers were surprised to find each bag released around 11.6 billion microplastics and a further 3.1 billion even smaller nanoplastics. These levels were, says the report, “thousands of times higher than plastic amounts previously reported in other foods.”

The researchers believe that the tea bags send so many microplastics because they are heated close to boiling point. And the researchers exposed water fleas (水蚤) to water containing varying concentrations of microplatics. While the animals did not die, they did display some abnormalities (畸形) that could suggest the microplastics were having a toxic (毒的) effect on them.

“To date, the health effects of consuming microplastics to humans are still unknown, while the effects observed in the present study and in other animals gave an early warning,” the researchers conclude in their study. “One of the main potential human exposure pathways of microplastics is likely via ingestion, and particle uptake may occur in the digestive tract. Once inside the digestive tract, cellular uptake (细胞吞噬) and subcellular translocation (亚细胞移位) or localization of the ingested particles may occur.”

1.What can we learn from paragraph 1?

A.Drinking tea is unhealthy for you.

B.Using tea bags probably takes in plastic grains.

C.People should often change the tea bags.

D.A tea bag is made up of microplastics and nanoplastic particles.

2.What do we know about the report in the passage?

A.The hot water can reduce more plastic particles.

B.The tea bags contain higher amount of plastics than everything.

C.The plastic particles exist in many other foods too.

D.The food industry has been greatly polluted now.

3.Why did the water fleas display some abnormalities?

A.They were poisoned by plastics.

B.They were not used to being exposed to hot water.

C.The water was heated close to boiling point.

D.They were put into different teas.

4.What's the purpose of the passage?

A.To introduce the study of microplastic and nanoplastic.

B.To tell us the contents of tea bags.

C.To explain the latest findings in plastic.

D.To inform us of the potential danger of using tea bags.