Mangroves are a complex group containing some 70 species. They range
from low shrubs to 60-metre-high timber trees. Though most prolific in
Southeast Asia, mangroves circle the Earth in a band within 30 degrees
of the Equator. Wherever they grow, they're brilliant at coping with
hostile environments. Although salt can inhibit plant growth, each
mangrove has an ultrafiltration system to keep out much of the salt from
sea water. Mangroves also have complex root systems that allow them to
survive in the intertidal zone. Some have snorkel-like roots called
pneumatophores that stick out of the mud to help them take in air;
others use prop roots to keep their trunks upright in the soft sediment
at the tide's edge.
These plants are forces to be reckoned with. Their interlocking roots
stop riverborne sediments from flowing out to sea, and their trunks and
branches serve as a valuable 'defensive fence' that absorbs the power
of waves during storms. Yet mangroves have been cut down in many
countries to make way for a range of developments. Since mangrove
forests act as natural breakwaters, mitigating property damage and
perhaps saving lives, the logic of allowing a country's mangrove
'bioshields' to be destroyed is being questioned.
1. The list below gives some of the positive features of mangrove trees. Which **TWO** of the features are mentioned by the writer?
请选择 2 个答案
A. They absorb very little salt.
B. They reduce the impact of bad weather on coastal areas.
C. They provide an ideal environment for shrimp to develop.
D. Their seeds germinate while still attached to the tree.
E. They can limit the loss of fresh water through their leaves.