Question 4
Original source text (the exact panel preserves diagram labels, tables and choices):
Leech therapy is a traditional treatment that uses live medicinal leeches to treat
diseases. The leeches’ saliva contains anticoagulants, anti-inflammatories, and
anaesthetic substances. By sucking blood, the leeches inject this saliva into the
patient’s body, which may improve blood flow, reduce pain and inflammation, and
promote healing. It is used for conditions such as arthritis, varicose veins,
cardiovascular diseases, and skin disorders.
Why does bleeding often continue for some time after the leech is removed?
A. Leeches secrete a specific toxin that reduces the blood’s ability to clot.
B. Leech saliva contains an anticoagulant substance called hirudin, which
prevents blood clotting.
C. Leeches rupture blood vessels, and the body does not have enough time to
repair them.
D. Leeches introduce bacteria into the body that disrupt the blood clotting process.
Leech therapy is a traditional treatment that uses live medicinal leeches to treat
diseases. The leeches’ saliva contains anticoagulants, anti-inflammatories, and
anaesthetic substances. By sucking blood, the leeches inject this saliva into the
patient’s body, which may improve blood flow, reduce pain and inflammation, and
promote healing. It is used for conditions such as arthritis, varicose veins,
cardiovascular diseases, and skin disorders.
Why does bleeding often continue for some time after the leech is removed?
A. Leeches secrete a specific toxin that reduces the blood’s ability to clot.
B. Leech saliva contains an anticoagulant substance called hirudin, which
prevents blood clotting.
C. Leeches rupture blood vessels, and the body does not have enough time to
repair them.
D. Leeches introduce bacteria into the body that disrupt the blood clotting process.