Some diseases are _____ by certain water animals.？

Certain programs work better for some _____ for

Certain programs work better for some _____ for

Some birds that are molting maintain balance during flight by______.A．constantly preening

We are ______ both by water and land, without either fleet or army.A．sensitiveB．susceptibl

Some people are quick－tempered ______.A) in natureB) in heartC) by natureD) byheart

To reduce the pollution, some industries are now______.A．treating the waste water containi