1. I wonder (why weather is so unpredictable). a. Prepositional phrase b. Adverb clause c. Adjective clause d. Noun clause 2. Storms still surprise (meteorologists who have years of experience). a. Prepositional phrase b. Adverb clause c. Adjective clause d. Noun clause 3. When lightning streaks (across the sky), people must pause many outdoor activities. a. Prepositional phrase b. Adverb clause c. Adjective clause d. Noun clause 4. (Until we can track all factors), we can't predict weather perfectly. a. Prepositional phrase b. Adverb clause c. Adjective clause d. Noun clause