A (chemistry) ______ must be familiar with many kinds of chemicals.
举一反三
- 中国大学MOOC: They are ______ in chemicals for many years.
- Environmental chemistry only studies the behavior of chemicals in the environment at the macro level, but does not involve the chemical mechanism at the atomic and molecular level.
- How many kinds of descriptions are there ?
- There are many different kinds of sports.
- As a defense against air-pollution damage, many plants and animals _____________ a substance to absorb harmful chemicals.