18．On October 31st, known as Halloween, dozens of children ________ costumes knock at their neighbor’s doors and yell “Trick or Treat” when the door ________.
| A．putting on; is open | B．dressed up in; opens |
| C．having on; is open | D．wearing on; open |
News came from the school office ________Wang Lin had been admitted to Beijing University.
| A．which | B．what | C．that | D．where |
The how to book can be of help to wants to do the job.
| A．who | B．whomever | C．no matter who | D．whoever |
One of the most important questions they had to consider was of public health
| A．what | B．this | C．that | D．which |
Could I speak to is in charge of International Sales please?
| A．who | B．what | C．whoever | D．whatever |
The fact has worried many scientists ______ the earth is becoming warmer and warmer these years.
| A．what | B．which | C．that | D．though |